Hey guys! First post here. So I've always associated solid state amps cranked on the clean channel with this horrible raspy kind of overdrive, but... well I'm a guitar teacher, and I bought a cheap old guitar/bass/organ montgomery wards amp for kids to use at the studio, and cranked it sounds amazing
What gives? What's going on in the circuit that makes one cranked SS amp sound awful and another sound very musical?
Thanks!
Oh, here's a gut shot--yes I've soldered that filter cap back in place since this was taken, haha
You are slinging the term solid state around as if it was the determining factor. Solid state means it isn't based on vacuum tubes, nothing more. Somehow I am reminded of my friend who has a little Volkswagen car with a diesel motor, yet I have another friend who drives a large dump truck, also with a diesel motor. How can they be so different, they are both diesels?
SOlid state doesn't specify much. Circuits in two amps can be VERY different. Different circuit, different parts, different speakers (very important part of tone), different enclosures.
I can't see it well, but is the date code on that loose cap from 1975? 40 year old caps can surely make an amp sound crappy. Just one possibility.
that's fair... but this 1975 amp sounds great cranked, lol
which is the question... why does this one crank into a very musical distortion while others don't? Is there something one "usually does" when designing an amp they want to be able to crank into nice drive tones?
Tried it through another speaker and the drive still sounds good so I know that's not the determining factor at play
Is there some thing? No. One sets out with a gain structure in mind. One then decides what sort of voice it wants to have. Consider the tone stack. I link below to Duncan Amps page. They have this really cool "tone stack calculator", a bit of free software you can download. It sets up several common tone circuits, and offers graphic frequency response in real time as you adjust the controls. If you look further into it you will find you can even change component values. And that is ONLY the tone circuit. Amp designers have to balane MANY factors.
https://www.duncanamps.com/tsc/
Quote from: Enzo on December 23, 2021, 11:42:38 PM
Is there some thing? No. One sets out with a gain structure in mind. One then decides what sort of voice it wants to have. Consider the tone stack. I link below to Duncan Amps page. They have this really cool "tone stack calculator", a bit of free software you can download. It sets up several common tone circuits, and offers graphic frequency response in real time as you adjust the controls. If you look further into it you will find you can even change component values. And that is ONLY the tone circuit. Amp designers have to balane MANY factors.
https://www.duncanamps.com/tsc/
I see. My best bet may be trying to clone this and then play with different parts/values to see how it changes things
Any source for the schematic? I know one in the same line was the 62-9133 but I'm not sure if it's the exact same one... this one had a 15" speaker if that helps
If not, should I ask in this room or in the schematic one?
Doesn't matter, we read them all.
I don't have any solid state Wards drawings.
Trace the circuit.
Draw schematic from that.
It shouldn't be too difficult.
I've drawn quite a few schematics for old, cheap, SS amps where the schem is unobtainium.
Search my threads in "schematics and layouts".
I found 2 Ward Airline SS schematics in my files.
Here they are.
Huh ? Those schematics look like wireless transmitters.
As Enzo has noted MANY things come into design and tone control is only part of what some call *System Tone*
By the looks of the picture posted it's and old style SS power section using an inter-stage Tx with a simple preamp front end.
The secret tone sauce you are hearing will likely be due to what looks like an "inter-stage transformer" which was widely used in those early designs.
Transformers are a big cost factor even for low quality units and as will be observed from later SState designs where they are mostly direct coupled to save cost.
You can still find some Tx coupled SS amps but co$t a lot more.
By design Tx coupling can have a magical effect on the outcome.
Now I'm not tecky enough to ez-plain every last detail but in simple terms they limit the bandwidth of the signal passing through them.
A lot of amps from early SS era (like yours) and most of the big name famous valve OTx's of years past used medium/low quality Tx's.
In fact the more power that runs through them the more the bandwidth is limited, delivering a sweet distortion.
So by design all the harsh hi freq crud is simply not able to be transferred from primary to secondary (Bass is also limited somewhat) which leaves you with a much sweeter smoother Overdriven tone.
You can design an audio Tx to pass full bandwidth (i.e. High Quality HiFi spec) but cost will rise dramatically.
Older designs tend to use less Neg Feedback which might have some effect.
There may well be some sag in the power supply as well which can help with the feel of the OD sound.
Now that does not mean you can't make great amp tone without a Tx,, you just need to approach the design stage with other tricks.
I use a Cab sim circuit and a few other tone shaping gizmos to attain a smoother Odrive tone.
Yes you could back engineer the circuit but the Tx will likely be hard to source.
----
As I've said many times after 30~40 years of building amps, pedals and many odd ball circuits I still have a lot to learn but the one thing that stands out from my experience is this;
If all you do is strum a few chords and play clean then bandwidth will not be much of a problem BUT the moment you want screaming od/distortion then wide bandwidth will just destroy any sense of magic mojo.
This goes for ALL types of Electric guitar styles, from Country to Metal they all require some tweaking to the tone shape and bandwidth when a lot of distortion is required.
----
Others here are for more teck savvy and maybe able to expand on the magic of transformers for you.
Merry Chrissy to everyone, Phil.
All great points Phil!
If anyone wants to study this concept further, check out the Peavey super-distortion patent (see Fig 3)
https://patentimages.storage.googleapis.com/66/73/f3/f482d05a548730/US4811401.pdf
You can legally build stuff from patents for your personal education/edification. If you pull out the distortion circuit, it makes a killer distortion pedal. Add pre and/or post distortion filtering of your own design for a personalized distortion box that no one else has!
Happy holidays, and thanks for an awesome website Joe and for all the great contributions from the power-posters. Here's to a rockin 2022!
Will
YES! An answer at long last... but of course it involved unobtainium :/
Would this work? 20 watts is about perfect...
https://www.ampmaker.com/shop/0-190-275v-20w-power-transformer/
Did I miss something? The transformer you link is for a tube amp. It has a 6v winding for heaters, and a high voltage winding for the B+. Not suited to a solid state amp.
Quote from: dmfp123 on December 25, 2021, 02:57:48 PM
YES! An answer at long last... but of course it involved unobtainium :/
Well there are several ways you can go; Buy a kit and poke parts into holes and pray it even works (with 97% chance of tears)
Or learn the basics. (it's taken me 30 plus years with no formal training to grasp how to achieve a great sound)
A lot can be gleaned from the net now and Several sites I know of some well worth the effort.
TeemuK's book Dload on amp design is right here on this site, go here;
https://www.ssguitar.com/index.php?topic=711.0
Also Rod Elliot's site has a massive amount of info aimed at folks like us who are not up to speed on the inner workings of amplification. Main page: https://sound-au.com/
A simple 20 watt chip power stage here;
https://sound-au.com/project72.htm
Click on, P215 [P27 Revisited] 40W Guitar Amplifier
A complete kit, from 20 to 100 Watt depending on Tr's used. I'm sure there are many other options around if you dig.
One idea might be trying out a few of those small little practice amps that go cheap in second hand op-shops, a lot of those use power chip amps such as the LM1875 which can deliver up 20 watts max,, Check out Project72 link above for some ideas using that chip.
Unlike your amp most SS power stages run clean and have a fairly wide flat bandwidth and although you can do a few tricks with the power section it's going to be easier for the novice to do all the tricks in the preamp. Personally I would suggest a simple single
channel preamp and then start buying or building a few pedals to get the OD.
I did find a pic of what looks like your amp last night and it looks like a large cabinet with a 15" speaker so as Enzo noted that adds to the result. https://reverb.com/item/2706505-vintage-montgomery-ward-3-channel-guitar-bass-organ-amplifier-15-speaker-usa
FWIW, I rely on pedals now and just use a very basic SS amp, Actually just an old SS Laney keyboard Amp.
For my sounds most fancy pants guitar amps are way to hot rodded. for SS amps I'd rather work with amps that have a simple less tone coloured response and let the pedals do the magic. most hot rod multi channel amps are frustrating as the clean is ok but the other channel/s are often useless and many players end up using pedals for most of the sounds they need anyway.
One wonders why bother spending big money on all the fancy channel switching crap if all you need is a simple amp and a few pedals. One big advantage of pedals is you can just swap them out if they don't work for you,,No solder needed. win win.
As much as I dislike the idea of a pedal board they prove to be far more versatile than expensive Amps.
If I can blow my own horn here;
I frequent a local open mic gig and the chap that runs it has more sound gear than I have ever seen in my life,, House is wall to wall full,purchases nearly every new Amp/pedal that he can find.
Now I've been playing that gig for 2~3 years so he knows me well and has often made positive comments on my sound. A while back he asked me if I could help him fine tune some of these new amps as he can't seem to dial in the right setting to get the magic.
he added "well you always seem to have the sweet spot and the magic sound"
hum,
I now have to find a kind way to let him in on the simple fact that nearly all the new gear is digital and he will be hard pressed to find any magic as those Vipers and Katanas are very harsh.
Most Guitar amp designs now tend to follow the music fashion trend (i.e. more hard edge metal) I've not yet heard/played one that can do the sweet blues thang.
If you are shredding fast arpeggios all the up to the 49th fret then I guess tone matters little.
If you want to start building your own gear,, be aware it becomes very addictive.
cheers, Phil.
Quote from: Enzo on December 25, 2021, 05:56:04 PM
Did I miss something? The transformer you link is for a tube amp. It has a 6v winding for heaters, and a high voltage winding for the B+. Not suited to a solid state amp.
Yes, well... as demonstrated I don't know what the heck I'm doing, lol
Any idea where to source a transformer with the specs I need? Or even what said specs would be? I think this Wards amp in question has something like 37 input watts but I'd be happy with something a little lower powered if necessary
Quote from: phatt on December 26, 2021, 07:21:11 AM
FWIW, I rely on pedals now and just use a very basic SS amp, Actually just an old SS Laney keyboard Amp.
For my sounds most fancy pants guitar amps are way to hot rodded. for SS amps I'd rather work with amps that have a simple less tone coloured response and let the pedals do the magic. most hot rod multi channel amps are frustrating as the clean is ok but the other channel/s are often useless and many players end up using pedals for most of the sounds they need anyway.
One wonders why bother spending big money on all the fancy channel switching crap if all you need is a simple amp and a few pedals. One big advantage of pedals is you can just swap them out if they don't work for you,,No solder needed. win win.
As much as I dislike the idea of a pedal board they prove to be far more versatile than expensive Amps.
Yes, agreed, I play many many genres but I never go more than... I don't know, Stray Cats-level overdrive, unless I want a really saturated neck pickup type lead for a soul/r&b part, but even that's miles away from "shredder" territory
The fixation on this particular amp... well, it's two-fold--educational (for the end user) and utilitarian
As I mentioned in my PM I'm a guitar teacher, and I always start my kids out on classical guitar. Invariably one day they either show up and say "I'm in jazz band now" or "I'm getting into this genre of music now" and at that point there's a fork in the road... most still play classical at that point but we start playing electric guitar then, too. This Wards amp on the bass channel is actually pretty fantastic for a piezo loaded acoustic guitar--totally rolls off all those annoying high end frequencies and provides some much needed low end, which is great because they can keep playing the guitar they have & just add a pickup, rather than buying a whole new guitar. For jazz that channel works well too, as do the other channels if you fiddle with the tone knob on the guitar... really 3 solid flavors of jazz tone in that one amp. Neo-soul is popular with kids now and that amp does it. Emo/indie/math rock is popular with kids now and that amp does it. If they want to learn something involving gain... it becomes an excellent learning tool for "this is how amps work, you turn it up and use your guitar's volume to control the amount of gain" etc. So... I guess in short, this amp does everything I need it to do without any fancy channel switching etc, and is really the only amp I've found that does that. The Yamaha THR series is still my go-to for kids who want to get into recording, but for performing purposes it doesn't cut it, it's not loud enough to keep up with a jazz band or even a drummer, let alone a high school drummer.
Of course... parents will often ask for a quieter solution for distortion lol, but I'm not always quick to tell them about pedals. Sometimes I want to force them to play clean for a while before I introduce "makeup for technique". Same with compressor pedals... can make some passages twice as easy to play, but as an educator... I don't always want that.
Obviously you are keen on replicating this amplifier so you will have to work out the circuit.
First you need to find out if the Tx is wired as an *interstage* Tx or if it is an Output Tx. (I'm assuming there is only one Tx?)
If it's an Output Tx then the speaker will be connected back to the Tx directly.
If the speaker is wired back to an Electrolytic Cap then the Tx is likely an interstage setup.
Of course I'm guessing a lot here.
If you really want help to build this then you will have to find all the transistor labels. (looks like there are 4 signal Tr's and 2 power Tr's underside. If you can't work it out then take clear well lit pictures of the front and back of the PCB and post them here.
No promises but I will try. :-\
Phil.
Quote from: dmfp123 on December 23, 2021, 11:48:28 PM
Any source for the schematic?
I could be wrong, but it seems we have not even found out the model # yet?
Perhaps that would be a little bit helpful? ;)
Mentioned on the first post, Also I linked to a few pictures I found on Reverb site in (post 15) ;)
Phil.
https://reverb.com/item/2706505-vintage-montgomery-ward-3-channel-guitar-bass-organ-amplifier-15-speaker-usa
Quote from: g1 on December 27, 2021, 02:28:37 PM
Quote from: dmfp123 on December 23, 2021, 11:48:28 PM
Any source for the schematic?
I could be wrong, but it seems we have not even found out the model # yet?
Perhaps that would be a little bit helpful? ;)
Quote from: phatt on December 27, 2021, 09:08:13 PM
Mentioned on the first post, Also I linked to a few pictures I found on Reverb site in (post 15) ;)
Phil.
I'm not trying to be difficult, but unless I am blind, there is no model # in either of those posts.
Schematics are found by model number. If we had the number, perhaps we would already be looking at the schematic, which would make for a much more fertile discussion.
Apologies if there is no model # to be found on the unit, but if so the OP should just say that.
Quote from: g1 on December 28, 2021, 02:52:44 PM
I'm not trying to be difficult, but unless I am blind, there is no model # in either of those posts.
Schematics are found by model number. If we had the number, perhaps we would already be looking at the schematic, which would make for a much more fertile discussion.
Apologies if there is no model # to be found on the unit, but if so the OP should just say that.
You aren't being difficult. The model name is "Guitar/Bass/Organ amp" by Montgomery Ward. There should be a model number as well though which no one has shared. This video shows one of the same name, but very different configuration (head/cab vs combo anyway) vs what was linked to by Phatt. https://www.youtube.com/watch?v=gWmjj-eag3g