The Schematics Stuff I've posted has gone missing but not to worry I'll repost a few here :tu:
The DDC (Dynamic Distortion Control) by itself won't blow your mind but by implimentation of the *PhAbbTone* circuit *in front* of this will reap some classic guitar tones from a bygone era.
(All these clipping circuits distort,,,, but this is very touch responsive.)
The addition of a simple cheap Graphic Equalizer *After* the DDC will deliver more tonal options than most music shops have Amps.
Yes I use these circuits in my setup and I play live gigs (although not to much these days) ;D
So I can vouch for their ability to deliver. :tu:
Phil.
Hi Phill,
Thanks for a refresh on your ideas here phill.
I am interested in asking you if you know a cheap circuit
for me to try in a way that i could "feel" the so called
tube compression...
sometimes i think i have some sort of problems with my ears!!!
after i did the presence control that is a cheaper version of
a cab sim... i think that 80% of the sound of the tube amp
is caused by filtering effect of output more the kind of wood
box (usually huge and expensive)...
the best stompboxes outthere uses cabsim...
WHAT I MEAN IS:
THE TUBES ARE NOT RESPONSIBLE FOR EVERYTHING IN THE SOUND OF TUBE AMPS.
Why people still keep believing that tube is so important???
besides it is not that cheap to make a real good vintage tube amp.
thanks
Actually "tube compression" is most pronounced when it is done with OUTPUT tubes. Also it is very apparent when the amp uses a tube rectifier and it creates a "sag". This can happen with a solid state rectifier but not as pronounced.
You ARE right that the "vintage" tube sound has other factors. These are sometimes deliberate as calculated resonant frequencies of good cabinets. Quality wood in the cabinet and type of speaker materials used.
Some of the "vintage" sound is actually due to deterioration in the type of components used.
You CAN change the sound some by using different capacitors of the same value. Orange drops , oil filled. polyesters all have a slight sound difference. Even Carbon composite resistors contribute toward that.
Some of the vintage sound was due to QUALITY of the tubes. Modern tubes are not manufactured to the same tolerances, and usually use different materials. The most apparent example of this is the 5881. Originally a milspec type there is negligible difference today between that and a "regular" tube.
That all said some of the tube sound stuff is hype. It usually is applied to a 12ax7 preamp. 12ax7s make good preamps, but the BEST tube sounds are from a hard driven OUTPUT 6l6 6v6 el34 7591 etc which is played through a speakers that handle but just barely the power that the amp puts out. Vintage tube amp speakers were designed to just barely handle the amps output. I remember how many I blew apart in the 60s.
When I play live in a large place using rig that includes Peavey Hybrids, Marshall JCMs etc. it ( output tube compression) is apparent. At low levels it really isn't. In the recording studio I actually use more Solid state with the exception of a couple of 5 watt tube amps. To drive the high power amps into compression would produce sound levels unusable to record. I actually have a work table full of 5 watter experiments to get a tone I want on the album I'm working on.
FWIW I have a Carvin SX amp that can sound more like my (favorite) 64 Guild Thunderbird amp cranked than any of the modern tube amps I own. Of course the Guilds Fenders Sunns and Marshalls are always on stage. Even if the Carvins are doing most of the work :D
By the way there is a caveat with output tube compression: If the amp is driven to that point you also have lag. The rectifier tube can't recover quick enough and you lose the beginnings of notes if your playing fast. Some amps start producing notes in there that you didn't play too!
Anyway look for that perfect tone that is in your mind...Don't care if it's from a tube or chip or transistor. If you have to go to a music store and play everything there. Then if you have to find the schematic and make one :D
I agree, tubes in the power amp do make a difference but each day I'm getting more and more convinced that the difference actually comes from the various distortion mechanisms and frequency response non-linearities, inherent to generic output transformer coupled tube power amp circuits, rather than from actual use of tubes. Solid-state amps emulating these mechanisms (e.g. Pritchard, Peavey TransTube, Vox Valvereactor, H&K Dynavalve etc.) do a pretty convincing job and the output waveforms of the circuits they employ can be tweaked to be pretty much identical to those of generic tube amps in overdrive conditions .
...Then again the whole definition of a "tube amp" is very broad and I've seen plenty of them distort quite differently than what the usual presentiment would make you expect. e.g. This is scope capture of a clone of one of those $$$ Trainwreck boutique amps driven to distort:
(http://home.polstra.com/amps/wreck1/scope/IMG_0688.jpg)
Kinda different from that "sweet soft clipping" prejudice. Hard, square waveish clipping and awful amount of crossover distortion. Yet, some people would sell their mother to get that tone. Most Class-AB Fender tube amps perform about similarly.
Hello Teemu,
Have a look at the dreadful *cutoff at V3* on the TW circuit.
Experts seem convinced that saturation is much smoother than cutoff,, yet as you note it maybe of little concern.
In My (limited) Experience, TW and really old Marshalls also,, The OT's have a very low primary winding and this (I believe though I can't mathamatically explain it)
Makes one hell of a difference to the end result.
I don't know the TW OT primary winding but I do know that some early Marshalls had very low primary. ie; 1700 Ohms pp.
This I think you will find forces limiting of bandwidth (under load) and definitly accentuates the *Second harmonic*.
BTW, Obsolete Electronics had a whole blab about this but the site is now ,,,well Obsolete :o
I have built a 6V6 Amp with a 6k6 pp OT and it was very harsh.
short story;
Went down to 2k6 pp and the difference was staggering.
Absolutely the sweetest sound.
Taught me a lot and opened my eyes as to what can be done.
As you may be able to tell I've learnt to train my ears a lot and I pay a lot of attention to the tone shaping,, SS or Valves.
Phil.
Quote from: rodriki1 on May 15, 2010, 09:52:13 PM
Hi Phill,
Thanks for a refresh on your ideas here phill.
I am interested in asking you if you know a cheap circuit
for me to try in a way that i could "feel" the so called
tube compression...
sometimes i think i have some sort of problems with my ears!!!
after i did the presence control that is a cheaper version of
a cab sim... i think that 80% of the sound of the tube amp
is caused by filtering effect of output more the kind of wood
box (usually huge and expensive)...
the best stompboxes outthere uses cabsim...
WHAT I MEAN IS:
THE TUBES ARE NOT RESPONSIBLE FOR EVERYTHING IN THE SOUND OF TUBE AMPS.
Why people still keep believing that tube is so important???
besides it is not that cheap to make a real good vintage tube amp.
thanks
Heck I don't think that you can get it much cheaper than what I've given here. ;D
How on earth do I explain it?
Tubes/bananas/transistors/fets, all of em distort.
The sound that you *Likely* refer to is power tube compression Which comes mainly
from power stage quirks of some famous valve amps. (*bry melvin* has covered some
already)
The only difference between Valves and SS is the simple fact the valves tend to
compress rather than just distort/clip.
The output of a SS power Amp will not do the soft compress trick so you have no
choise but to make it happen in the preamp stages by using some circuit tricks.
I choose to do it the tried and tested way,, only twist is I impliment the tone
circuit and add a cheap GEQ.
(I'll never win awards for it but it gets some great sounds)
Worth a mention;
(This is why a Tube screamer will sound quite stunning through an old valve amp from
yesteryear but plugged into a all SS Amp it may well sound harsh/fizzy,,very different to say the least. Some Classic tube circuits rip off a lot of high freq hash in the output stages whereas SS amps do the exact oppisite,,so you tend to get all the high freq crap which destroys any smoothness)
Once you can grasp that tube amps work very differnt from SS you will see how darn
important the tone shape is.
Tone is everything if you are trying to extract specific sounds of certain genes of
music.
Forget Wood, Valves and PU's and all the hype, Understand this simple observation.
Tone is just the shape of the frequencies amplified,,, more importantly the ones
that *Are Not Amplified* deliver better results.
*****It's about what you don't hear that makes for fantastic guitar tone*****
Some classic tube amps did this tone shaping by design so when designing SS gear you
have to be very aware of this point.
(my favorite setting with above circuit is a big deep notch CUT @ 300/400hZ *Before distortion* and then cut again *after dist* at 800/1000hZ)
In other words you achive vastly better results by cutting certain frequencies then boost the gain.
Then you get far less circuit noise which means you have heaps more head room before
the dreaded noise/hiss of stupid hi gain stuff.
And that is how you get great distortion sound even with simple cheap SS gear.
If you have access to a *parametric EQ* then use that in front of a dirt box/TS99999,(Pick a model) Then use a graphic after it.
Again The trick with paraEQ is to *CUT,,,NOT boost*.
The Graphic; try a flat setting and just full cut at 1khZ.
Even without the Cabsim this alone will make a big difference.
Worth a mention is Speakers.
I'll tell you a little story;
My friend of many years came to me with his Teck21 Trademark60.
He simply asked if there was any way to make it sound like my gear.
I won't bore you with details but he was stunned at the result.
I simply replaced the speaker with a far *LESS Efficent* speaker.
***Remember***
Modern Amp makers use very high SPL drivers simply because the louder it sounds in
the shop the better chance of a sale.
(apparently young minds only respond to loud sounds)
High SPL drivers are ALWAYS Highest output in the 3khZ freq range and this makes the
amp sound a heck of a lot louder but you pay for it in tone,,,Harsh as all hell.
If you are chasing the sweeter tones of older amps then use of freaky slick named drivers is likely to seriously impair your progress.
The older less efficient drivers generally deliver a sweeter sound,,Hint.
Have fun,
Phil
Just adding this mud map showing how the 3 units are linked.
True Bypass on everything really helps when using different Amps/gear as you often need to find out the response of what you plug into.
Makes for a more versitile setup.
The other though here is that all 3 could be housed in a floor unit if you so wished but you will need a stomp GEQ for that.
I've housed it in a small rack and I tend to leave it set to one sound as it's so dynamic I don't need to keep changing it.
I use a small fet signal booster stomp pedal if I need a little more drive.
Just giving some ideas for you all to kick around.
Phil.
Tone shaping... YES. That's where it's at!
Just to add, if you study just about any modern hi-gain amp you most likely find plenty of drastic hi-pass filtering before the overdriving stages. Usually many high-gain amps start to cut low frequencies heavily already at about 1 kHz, which is kinda counter-intuitive at first considering that frequency of low E is about 82 Hz. And that's pretty much the trick that separates muddy, fuzzy and farting distortion tone from creamy smooth distortion or snappy, ear-piercing treble. Too little: you get muddy, fuzzy tone (e.g. Laney Klipp amps). Too much: ear bleeding treble and nice bluesy clarity but not really enough balls to strum those heavy metal palm muted riffs. Low frequencies can really kill the distortion tone. Rest of the frequency shaping is pretty much just killing the "fizz" or voicing the distortion tone in various different manners.
If you wonder why people used treble boosters with tube amps it's just because of this: Drastic low frequency cut by boosting gain of higher frequencies - as a side effect it really helped to overdrive the tube amps (which at the time were mostly designed to produce the signal cleanly). The Tube Screamers were practically the same story: Many used them as a rather "clean boost" (with distortion dialled to minimum) - but in fact, the term "clean" in that case is somewhat misleading because those pedals happened to boost mid-range quite drastically by cutting low frequencies as well as highs. So, it wasn't a mere boost, it was once again important tone shaping for overdriving stages to follow.
QuoteKinda different from that "sweet soft clipping" prejudice. Hard, square waveish clipping and awful amount of crossover distortion.
+1
I don't know why that old wive's tale of "tubes clip rounded, SS clips square" and "tube has even harmonics, SS has odd ones" is still being sickeningly repeated over and over, zillions of times, specially by people who should know better, I mean famous name factories, boutique builders and "tube gurus".
Just for kicks, scope the output of a Plexi when overdriven by 10/15dB , loaded by a real world speaker, 4x12" welcome.
It will be like nothing you ever imagined; "complex dirt" indeed.
"Rounded sinewave" my 4ss !!!
thanks again for the ideas here.
I just think here in my country is very expensive to buy a famous tube amp.
I like to know that some of you are willing to share the ideas and impressions.
as you mentioned there is a video of Brian May showing (in his opinions) how vox sound
bad without treble booster...
http://www.youtube.com/watch?v=nHEwL-Tqo7M&feature=related
very interesting
regards
QuoteWorth a mention is Speakers.
I'll tell you a little story;
My friend of many years came to me with his Teck21 Trademark60.
He simply asked if there was any way to make it sound like my gear.
I won't bore you with details but he was stunned at the result.
I simply replaced the speaker with a far *LESS Efficent* speaker.
***Remember***
Modern Amp makers use very high SPL drivers simply because the louder it sounds in
the shop the better chance of a sale.
(apparently young minds only respond to loud sounds)
I like the sound of my little 5W amp, but I sure wouldn't mind a less efficient speaker if for no other reason than to make it quieter. When my wife is across the street at her grandmother's house, she can hear what I'm playing, and practicing with the amp after the kids go to bed is out of the question. I also do not like the way it makes my ears hurt when I've got the master volume cranked. I use a little sh#tty digitech RP-70 as a headphone amp for quiet practice, and it's just not the same as playing through a real amp. I think I might start looking for some old speakers to see how they sound. I added an external speaker jack to my amp, so experimenting with different speakers should be fairly easy.
BTW, next time I go to a thrift store, I think I'll pickup whatever old eq they have. :tu:
Quote from: rodriki1 on May 16, 2010, 05:20:41 PM
thanks again for the ideas here.
I just think here in my country is very expensive to buy a famous tube amp.
I like to know that some of you are willing to share the ideas and impressions.
as you mentioned there is a video of Brian May showing (in his opinions) how vox sound
bad without treble booster...
http://www.youtube.com/watch?v=nHEwL-Tqo7M&feature=related
very interesting
regards
Hi Rodriki1,
Yes everyone knows about the famous treble booster,,, but it's kinda useless unless you plug into the *Correct input* on a Vox Amplifier.
Remember there are *6* inputs on the Vox.
normal x2
bright x2
Trem x2
****Opps, No one ever mentions which one he used?**** :o
The *Normal Channel High* is the one to use as it bypasses any tone stacks.
If you care to follow the signal path of the *Normal Ch* you will see that there is ONLY 1 preamp stage > volume pot > into PI and powerAmp setion.
Only the *top cut* control effects the tone while using Normal Ch.
Use of the other channels will NOT deliver the BM sound.
Take note that Brian demonstrates the sound without the TB engaged and it's very muddy indeed. (trained ears can tell there is no tone stack)
Still very dynamic, as evidenced by simply rolling of the volume on the guitar.
But this is exactly what you want to happen,, the raw dist sound is all there you just need to wipe off some bass. (Tone Shaping again)
This delivers the full midrange sing song effect of His sound.
(Interesting to note that the raw sound of my DDC circuit sounds just like the raw sound of the Vox normal ch. :)
The problem with chasing exact tones is Most guitarist don't play all Queen music and what happens if You need another type of sound? :'(
It's fine when you are rich you can have any gear you wish but when you exist on a very strict budget (Like Me) you can't afford to waste money on a one trick pony.
You need something a lot more versitle and not to complex to setup.
My thoughts on the B May signal path.
Note that there is only One half of an AX7 before the PI and power tubes. 8|
Does make you wonder why so many Valve amps today have so many preamp tubes yet a lot of those Amp's still can't quite capture any meaningful tone :loco
Cheers, Phil.
Quote from: rowdy_riemer on May 16, 2010, 11:27:13 PM
QuoteWorth a mention is Speakers.
I'll tell you a little story;
My friend of many years came to me with his Teck21 Trademark60.
He simply asked if there was any way to make it sound like my gear.
I won't bore you with details but he was stunned at the result.
I simply replaced the speaker with a far *LESS Efficent* speaker.
I like the sound of my little 5W amp, but I sure wouldn't mind a less efficient speaker if for no other reason than to make it quieter.
BTW, next time I go to a thrift store, I think I'll pickup whatever old eq they have. :tu:
Hi, Can I enquire if the little 5Watt Amp is a Valve unit?
If so you can do some tricks by ReAmplifying it and then run it through the cheap Graphic (you will no doubt find at a junk sale) then into a second amp.
I've done that trick to a simple Valve Amp, with great results.
No one wants those old HiFi type EQ's anymore so they tend to sell dirt cheap. :tu:
Phil.
Quote from: J M Fahey on May 16, 2010, 02:38:49 PM
QuoteKinda different from that "sweet soft clipping" prejudice. Hard, square waveish clipping and awful amount of crossover distortion.
+1
I don't know why that old wive's tale of "tubes clip rounded, SS clips square" and "tube has even harmonics, SS has odd ones" is still being sickeningly repeated over and over, zillions of times, specially by people who should know better, I mean famous name factories, boutique builders and "tube gurus".
Just for kicks, scope the output of a Plexi when overdriven by 10/15dB , loaded by a real world speaker, 4x12" welcome.
It will be like nothing you ever imagined; "complex dirt" indeed.
"Rounded sinewave" my 4ss !!!
I read somewhere that half wave clipping followed by square wave compression is what happens.
In my limited building of Valve gear :D
Triode preamps do deliver the aysimetrical wave but it's the power stage square wave thing that is most usefull.
As I've just been revisting B May it 's interesting to note that with just a simple one triode preamp (which by itself can't do very much distortion) You only need to send the thing a bigger signal swing and Presto! all the magic power tube stuff just jumps straight out.
Phil.
QuoteQuote from: rowdy_riemer on 16 May 2010, 22:27:13
Quote
Worth a mention is Speakers.
I'll tell you a little story;
My friend of many years came to me with his Teck21 Trademark60.
He simply asked if there was any way to make it sound like my gear.
I won't bore you with details but he was stunned at the result.
I simply replaced the speaker with a far *LESS Efficent* speaker.
I like the sound of my little 5W amp, but I sure wouldn't mind a less efficient speaker if for no other reason than to make it quieter.
BTW, next time I go to a thrift store, I think I'll pickup whatever old eq they have. Thumbs Up
Hi, Can I enquire if the little 5Watt Amp is a Valve unit?
If so you can do some tricks by ReAmplifying it and then run it through the cheap Graphic (you will no doubt find at a junk sale) then into a second amp.
I've done that trick to a simple Valve Amp, with great results.
No one wants those old HiFi type EQ's anymore so they tend to sell dirt cheap. Thumbs Up
Phil.
It is a valve unit. It's a Peavey Valveking Royal 8, with a few mods. I may do the re-amping thing. It sounds like a good idea. But I definitely would like to keep the setup as simple as possible for practice. I might try one of the various power attenuator projects out there, but I know they've got to have some effect on tone. I guess intentional impedance mismatching could also maybe help. Do you have any suggestions for a re-amping setup?
Hi,
some time ago i have done some experiments with the Idea of LXH2 site.
i have made the LOW VOLTAGE power AMP (as they stated, genuine power amp
distortion with low power) using op amps as preamp and
two El84 as pushpull output...
i live in small apartment and i still found it was too much sound
for a low power amp (i used a generic 12" speaker i found in a store here)...
besides that a made another amp based on the LM388 chip using
a preamp with two simple diodes for distortion (just like boss DS1,
MXR distortion,guv´nor and so on). I used 1n4148 diodes.
I decided to compare the sound of the two amps.
i was expecting to have a HUGE diference.
but for my surprise the simple SOLID STATE AMP sounded quite
the same thing.
The El84 amp was more fat and bright...
but i think that the cost of the tube based circuit was very much higher.
considering that i wired the output transformer with my own hands, it was
too much work...
to make my sound test i used one mp3 player as the input of those two
amps (playing some guitar riffs) and recorded the samples of output....
I swear i could make a blind test using those amps and people
would very hardly capture the diference.
I ask my self if could tell from the results i got, that tube amp for lower voltage have a cheap sound???
Or that we can really get the sound that we want from solid state????
thanks
the amp from LXH2:
http://home3.netcarrier.com/~lxh2/lowpsch.html
the sample of the amp with lm388
http://ladelec.com/practicas/circuitos-analogos/336-amplificador-para-radio-de-am-con-lm388.html
QuoteOr that we can really get the sound that we want from solid state?Huh
Well, there's these crazy :duh guys from SSGuitar, which claim that it can be done.
Maybe they have something. 8|
There's obviously a lot of convincing ss circuits out there. After building a dr. boogey, it's hard to imagine forking out $2000 for a similar sound. Of course that's all preamp distortion. And of course, there's good emulation of power stage distortion. After getting a tube amp, I really like the way it sounds clean, especially with single coil pickups. It's the clean triode sound that I think might be hard to emulate. But then again, my experience with different amps is limited.
Attn *rowdy_riemer*
Re "suggestions for a re-amping setup"
----
Good Your little 5watt is a perfect candidate for soaking and ReAmping:)
Attenuators look appealing as it's a simple add on but they are very limiting.
I've found them painfully frustrating till I understood you can bypass most of the issues surronding the losses with attenuators by simply running a soak and tapping the signal off to another Amp.
(The 2 ideas are very similar and it often gets confusing)
The *Second Amp* drives the speaker (The UA does this all in one box)
A simple resistive load soaks the power tubes and via simple voltage division is converted back to line level.
Run this soaked output through a simple Graphic and into a SS power Amp of your chosen wattage and you will be way ahead for a very small outlay.
Now you can go crazy and not annoy the folks next door. ;D
The pics should tell you most of it but may require some explaintion.
The load resistor for your 5Watt amp need only be 10Watt (you can go smaller but the cooler things run the better)
The box here runs only warm with my little 10Watt Amp.
The ground Lift will come in handy as you will no doubt have a second amplifier that is also grounded ,,trust me this sw will come in handy.
The Load R;
Assuming 8 Ohm output from tube amp then an 8 Ohm resistor will make for a very flat compressed output.
running 24 Ohms delivers a far more realistic dynamic response but will still need tonal adjustment to make up for losses.
Sadly there is probably no *perfect system* there will always be some loss when implimenting these things.
SS or Valves, you will loose some realisum when you turn the SPL down to very low levels but Any loss is far out weighted by the amount of tricks you get to do with this.
Have fun, Phil.
Cool, thx for the info. I'll definitely give this a shot. BTW, I just picked up a stereo eq yesterday at the thrift store. Only $5.
Quote from: rowdy_riemer on May 18, 2010, 08:52:58 AM
Cool, thx for the info. I'll definitely give this a shot. BTW, I just picked up a stereo eq yesterday at the thrift store. Only $5.
Arrh, That's what we like to hear,,, *Cheap* ;)
I just mount 6.5 sockets in the back panel and install internal jumpers across to the RCA sockets otherwise it's a pain to work with RCA
The other channel is obviously not used,, So a spare eq for something else maybe.
Just watch out for the top line models with the *stereo wide function*.
I have one like that and it does funny things when engaged as you are only using one side and hence mono signal.
If you happen to have a rack processor (with stereo out) or similar gear you can now do all the fancy time effext *post Power tube* into a stereo power Amp and two speaker boxes.
I think you will have a lot of fun with it.
Cheers Phil.
first thanks for posting the schematics , those are very good circuits. Now for the The tube amp tone.
That tube tone (compression, and everything else ) is acommplished as a effect of the entire system not just a single component or group of components. the best compression I have heard myself was from a old Marshall JCM 800 2204 if memory serves me, but if you check out just about any vintage tube amp most components are well out of the 20% tolerance , yes sir 20% , that is also another one of the factors that give ya that tube mojo lol . Then you have the xformers which greatly alter tone as far as that goes experiment with some simple inductors in these Solid Stae circuits it will surprise you the tone you can get out of them. As fair as the filtration goes guys it's really pretty simple in a tube amp there is far more filtration goin on in solid state amps , however with that said yep that influence's the tone too lol lol . as for the vintage cabs I'm sorry folks , but a cab made out of pressed wood with the same dimensions and with a good quality guitar speaker(driver) will give ya just as good tone as that old vintage cab.
Now , as for the tube amp emulation , yes there are some out there that get fairly close , close enough , most people don't ave a clue as to the difference in tone. However , I'm sorry guys if you what it to sound like a Marshall or any other tube amp , buy that amp , no emulator is going to sound exaclty like that amp.
Rock On
Jack
QuoteNow you can go crazy and not annoy the folks next door. Grin
Now this advice should be taken with a grain of salt, considering that in Australia "the guy next door" may very well live 450 miles away, so a 1200W amplifier could be considered "a bedroom amp".
Ever heard of "The Outback? :lmao: :lmao: :lmao: :lmao: :lmao:
(http://www.worldwidewanderings.com/Dcp02971.jpg)
Hi JMFahey,
Very good,, very funny,, I'll pay that one, LOL.
I live on the north side of the fence,, the Dingo side.
BTW Not ALL of Australia looks like this,, Though the centre is very much a no mans land in places.
Some roads out there you can drive at 140 MPH for hours,,, DEAD Flat straight.
It's quite errie at night.
Cheers Phil.
Yea, I know. Mind you, in Argentina we also have a-couple-hundred-miles-straight roads and places compared to which, the Outback looks like a tropical garden
Just for kicks:
(http://www.sanpedrodeatacamahoteles.com/blog/wp-content/uploads/valle-de-la-luna.jpg)
,
(http://www.lasescapadas.com/wp-content/uploads/2009/01/ischigualasto-1.jpg)
,
(http://www.sw-computacion.f2s.com/Fondos/SW-ValleDeLaLuna002.jpg)
and
(http://www.lasescapadas.com/wp-content/uploads/2009/01/ischigualasto-31.jpg)
,
As a side note, I am not writing from Australia (or Canada or even the US), simply because at Liverpool docks, my family boarded "the other" ship.
Out of the way places are handy for a working/practicing guitarist
This album art was taken in my yard http://sunsets.arivacaart.com/home/back%20cover.jpg?attredirects=0 (http://sunsets.arivacaart.com/home/back%20cover.jpg?attredirects=0)
The eq I picked up had a dead left channel, which would be fine since I only need one. But I just hated having a dead channel, so I pulled it apart and tried to diagnose the problem. None of the electrolytic caps looked bad. I couldn't see any problems with cracks in the pcb. But I did notice that each channel had a 4558 dual op-amp. On the left channel I could detect a signal on pin 6(+ input), but there was only a 60 Hz signal on pin 7 (- input) and pin 8 (output). Well, I knew that wasn't right, so I pulled that 4558 off the board, and soldered in another one. That did the trick. I know that's a fairly simple fix and not too big a deal, but being that that was the first factory-built audio appliance I successfully trouble shooted and fixed, I was pretty happy about it. :)
Congratulations. That's about it. Good troubleshooting skills !! :tu:
Thanks, JM.
Hi Phatt, thanks for sharing these schematics and all your other info. I plan on breadboarding the Phabtone soon when I get my hands on some TL072's (next trip to jaycar). I was digging around and checking out some your old posts - Your sound clips sounded great!!!
A couple of newb questions...bear with me as I don't have any history of electronics. Just what I have read on forums, books for past few months.
You mentioned on some older posts that the tone stack section was from a Hiwatt amp.
1. Would it be possible to take the input/tone stack section, say everything from the left of C6 in your Phabtone schematic and add that to ANY low watt SS amp circuit? For example, looking at the runoffgroove schematic for a Ruby amp (apologies if you don't have one handy) - could I take your input section and wire it to pin 2 of the lm386 used in the ruby - kind of in the way there is a Fetzer ruby or Marsha ruby?
2. How would either the tonestack or whole phabtone go as the pre for a LM3886 amp?
I should state that i'm looking for clean(ish) amp tones and tend to use pedals when i want distortion. Is the phabtone what I should be looking at?
cheers
Steve
p.s
Nambour hey ;)!! Not much desert there, in fact the soil is sooo good just look at how big the pineapples grow:)(http://www.smh.com.au/ffximage/2005/06/16/bigpine16_wideweb__430x280.jpg)
Also the birthplace of our former Primeminister - Kevin 07 - lets not go there shall we :'(
Hi Dogbox,
Arrh obviously you're an aussie? :tu:
Yes the big pineapple is down the road from me.
Sadly the tourist trade has suffered in recent years and it's now all sold an no longer running as a resort.
Re the the tone box;
In a word no on both counts.
These Valve type tone controls are *High impedence* circuits which suck the life out of any voltage gain and with no Active component to recoup the loss,, it's a dead end street.
A 1 Volt signal in can be reduced to about 300 mV,, that's on a good day.
The loss can be worse if it's not looking into a very high impedence.
You can lose heaps of Bass this way and you end up with tone controls that only sorta kinda work.
My tone box was designed with the idea of just delivering Real tone control that is lacking in a lot of Amps. (yes even some Valve ones)
Re running the PhAbbTone direct into LM3886;
Having just returned from the shed after testing the PhAbbTone circuit straight into my little LM3886 sub woofer,,, You will likely need another stage. :'(
Check my preamp circuit for LM3886 I brewed,, you will likely have to turn down the gain if you desire super clean or just add a trim pot for gain adjustment.
(look at how the volume/gain/trim pot is used on the PhAbb circuit for ideas)
Re Your idea of Clean;
Be very aware that everyones idea of clean can be quite different.
Some folks would be quite supprised to learn that Hank Marvin's Sound had some distortion happening to the signal,, even though you might consider that sound pure clean tone,, It's Not.
Some rattlin adds a certain about of body/depth to the sonic signature which is why a lot of early SS Guitar amp where a flop because they just refused to breakup at all.
Ultra HiFi Clean can be very unimpressive and boring to play.
That said I'm sure some like it.
Anyway keep reading and suck up as much as you can.
A bread board and some components will soon get you in some understanding of how it all comes together.
Have fun,, Phil.
Thanks for that Phil. Yep another Queenslander, living at Beenleigh for many years :D I actually grew up in the 70's at Tewantin, and in those days Nambour was considered the big smoke-it used to be the capital of the Maroochydore shire council at one stage!!! Times have changed huh? A number of years ago they moved the hiway didn,t they?. In some ways that could be seen as a good thing-from what I have seen of the rest of the Sunshine Coast has gone mad-they are loving it to death...
OK then, a double-"no" to my questions - I'm thinking the Phabtone may be better suited going into my Epiphone valve Junior which has one volume pot? Not a bad little amp but definitely could benefit from some tone controls PRE the input jack as its a bit of a one-trick pony? It does sound great with pedals though.
Will try and track down your preamp schemo-haven't found that one yet. Yeah I definitely have got the breadboarding bug and slowly building up a part stash, only working on 9v stuff so far - Ruby amp, tillman jfet preamp, fetzer valve etc etc soldered a couple of jaycar and effects pedal kits - love this stuff.
Will be getting around to doing a LM3886 kit from chipamp.com in the future-have it here, just afraid of getting zapped if/when I start playing around with mains voltages. Will probably annoy the heck out of everyone when I get started on that project ;D
Plenty of reading to be done first though - this forum is a great resource.
cheers Mate
Hi Dogbox,
Preamp for LM3886 is here;
http://www.ssguitar.com/index.php?topic=1672.0
Halfway down page.
Have a look at the gut shoots on my last posting on there, might give you some ideas of how you might build it all.
The hand drawn pcb preamp board should be rather obvious and although the main board looks complex it's only the centre bit that is used. All the rest is disconnected or removed as that is the sub circuitry and remote sense stuff.
Oh you poor man if you have to endure *Beenleigh* as it's just an extention of brisbane now. :(
I moved from Brisbane to get away from the stupidity of the big city it has become.
My Uncle ran a pineapple plantation (years back) at Woombye (Near the big pineapple picture shown) so I knew this area well from my youth.
Now I live here, an I love the country town feel.
Phil
Hey Phatt,
That looks great. I take it that IC is an opamp? If so, which do you recomend? I have a bunch LM741's would that work??
Yes true Beenleigh is getting that way too, we were part of Albert Shire (gold coast) then swapped to the Logan Shire after the last election - so you could say we went from Gold Coast North to Woodridge South in one foul swoop ;D
Breadboarding this pre looks like a good project for the weekend-after a trip up to Jaycar on saturday morning.
cheers for that..
Hi mate,
Yes you can use the uA741 or similar,, just remember the pinout is different.
Ask Jaycar for a couple of LM833 dual opamps,, these are technically far better than 741 but really it won't matter much while you are breadboarding stuff.
You may find the 741 (being a single unit) are easier to work with while breadboarding.
You can setup a split power supply just with 2 x 9V batteries in series.
The mid point between them becoming the *Common or Ground* refference.
Use LM833 or TL072 when you build the PCB though.
Phil.