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12w Marshall

Started by Tassieviking, July 22, 2022, 01:39:40 PM

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joecool85

I'm super excited to hear this playing!
Life is what you make it.
Still rockin' the Dean Markley K-20X
thatraymond.com

phatt

Quote from: guzzis3 on January 18, 2023, 09:05:19 PMHi,

If you had to order extra PCBs that you want to sell I'd be very happy to buy them from you. I am in Brisbane,

This is my first post to this forum. I was pointed to this thread by a person on the marshall forum. I've been building electronic stuff since I was a kid but while I have built quite a few valve guitar amps I've not built a SS one.

 Have you determined if the 5005 etc develop their distortion in the preamp, power section or both ?

I realise you haven't finished your design, and there may be problems, but starting even with a flawed PCB is probably easier than laying it out on tag strips or breadboard.

Thank you for reading.
Hello Guzz, just note on SS rigs,
Most do not respond to power stage distortion, some rare ones try to do that but likely not as convincing as a full Valve powerstage.

With SS Amps all the dirt, grit, compression and like attributes of Valve amps needs to be done in the preamp stages.

My main rig is just a basic SS amp and all the magic is done with my pedal board. Most of the pedals are my own design, some of my schematics are posted on this site.

40 plus years back I wanted to build an amp that did it all in one rig.
Took me many years to realize that I was just building land fill.
I now  have draws full of failed ideas (other wise called spare parts 8) )
I have built both Glass and Sand designs and although I like Valves there many benefits to SS designs.

If you are lucky enough to find an amplifier (Glass or Sand) that works for you then lucky you, sadly more often than not you'll spend a fortune trying to find it.

BTW I'm up the road in Morayfield if you want to make contact I'm happy to help with my years of researching. Just pm me for my phone number.
Phil.

guzzis3

Thank you for the replies.

Morayfield! Goodness it's a small world. I'm at Mt Crosby.

Yes I now unfortunately am on the pension. Humiliating but I'd run out of options. The blindness is one of several problems.

I found your thread on the 100W models also. I assume all these generate clipping in the preamp and you can dial it in at different volumes ? Maybe I'll build one of those instead. I have developed an interest in stereo setups though. Some of the effects sound a lot better on 2 channels. I could hang on to the 8008 and build a preamp to feed it. Another option.

A PCB would be helpful though. I've built on..tag strips ? before. I forget what they are called. When you get a lot of components that can get messy. Building a pair of preamps though should be manageable.

Limited component availability is disappointing.

I'm not looking for distortion, just an amp with terrible frequency response :D I've got a Boss GT8 and of course if I want a singing sound I've any number of valve amps to play with.

I have grabbed an 8020 and VS15 at very good prices but it's surprising how disappointing both are. The VS15 oddly seems to be the nicer clean amp. The 8020 need a bit of help. Reverb seems not to work and I suspect other problems. Perhaps there is a mouse living in there.

I have a plexi marshall major. Bought it when I was young and dumb. There was a super lead, lead and major second hand. The lead and major were the same money, the super lead was out of my price range. It would have been better had I bought the lead but I figured if I couldn't be good I'd be loud :D Oh to be young again.

phatt

Hey Guzz,
I assume when you say *Terrible Freq response and then Boss GT8 in the next sentence* then you are maybe chasing the old sweet magic of limited bandwidth valve gear.
This can be done with SS gear but you have to in a different manner than you do with Valves.
Phil.

guzzis3

I have several valve amps. I've built quite a few over the years but people keep talking me into selling them, then I have to build more. Blessed bother.

These last some years I have had many occasions when I have maybe 1/2 hour or something for a quick practise. I am reluctant to use valves for this. I have a limited stock of old valves and when they are gone I will be condemned to the modern market of overpriced NOS or awful new valves.

So I went looking for an alternative. SS is the obvious answer. It needn't distort but I would like something "nice.

I bought a Vox Pathfinder 10, too bright. Marshall VS15 (UK) nicer but still a bit glassy. 8020 despite the 10" speaker is ok but not great. It also needs repairs. Reverb does not work and I suspect there may be more amiss.

I got a Hotone Boogie Siva which arrived the other day. I've ordered a second. VERY nice clean amp. No distortion but it sounds like a clean valve amp. Into a 2x2x12. I'm quite shocked.

Also as a result of my gumtree ad a chap in SA has contacted me about swapping my 8008 for his 8200. The bi chorus has some issues (seems common among the valvestates). We shall see what comes of this.

Not sure what I am going to do with the valvestate combos. The hotones will do me just fine. I am quite surprised at how nice it is. Perhapse if the price of the purple wind or the vox copy (can't remember the name) come down I'll get some of them. At $140 though they are a bit rich for me atm.

phatt

#20
Go here for real in depth insight into guitar amp tones.
The end will likely make you wonder why no one ever researched this before.
I've been quietly babbling on about this for years but this chap pretty much puts it all together well.

I'm not a marshall fan mainly because they only have one trick and the tone controls are pathetic. (though I'm sure many will argue) lol

https://www.youtube.com/watch?v=wcBEOcPtlYk


I use an old Laney Keyboard amp which is super clean.
Everything else is done with my pedal circuits, half of those are my own designs

I can produce Hank clean all the way to ZZ top at the press of a button or 2.
If you have built amp/pedal circuits then it will not be hard to work out how it's done when you see the end of the video  8)

The game of guitar tone is in understanding the frequency range the guitar needs. most gear today has insanely wide bandwidth and it totally destroys your tone (Especially for hard driven OD tones).
You have to dramatically limit the bandwidth for rock guitar sounds otherwise it's just one clangorous mush of eFd up noise.
which is why I steer clear of all in one pedal like Boss GT's as they have way too much hi freq crud and tonal adjustment is limited.
Go build some pedals and save a fortune and your back ,,,winky Phil

guzzis3

I have invaded this thread and it's drifted way off topic. If you really want to continue this line of discussion please start a new thread.

I will just make one more comment though. I can build a valve amp in a few hours. I've never built a copy valve marshall. I avoid complicated preamps, I've never really used the tone knob on the guitar let alone preamps on an amp. Volume is all I need. I just wanted a nice clean amp for quick practice not a deluxe rig. I've been quite surprised at how hard this has been. 3 practice amps, all very ordinary. I have ordered a second hotone boogie siva. I don't know what they did with that but it sounds very nice and at $72 delivered it's cheap enough. It will do.

It still might be interesting though to build a stereo Lead 12/30 or whatever and see what can be had from that into 2x2x12 speakers.

It is afterall just a bit of fun :)

phatt

All good, Just throwing in some observations from my experience sorry if you think it's off topic.
Phil.

Tassieviking

Guzzis3, where are you getting the Hotone Boogie Siva for $72 from ?
I might be interested at that price.

I am not worried if this topic has drifted a tiny bit of topic, and I started it.
As long as I find out new things I'm happy.

I am especially happy now since I have found out about the Hotone Nano series.

Michael.  :)
There are no stupid questions.
There are only stupid mistakes.

guzzis3

Ebay. The seller is in Australia and the power supply is correct. It's very clean, no distortion at all but I think it must have some shape to the response curve, probably drop off at low and high like a valve amp. $71 and some cents.

Getting into ambiguous terms. I don't have a spectrum analyzer so I can't be precise, but it sounds a bit warm or creamy or something, not cold and precise like say a hifi amp with the impedance fixed to accept a guitar in. By comparison the 2 valvestates and the vox pathfinder sounded "glassy" clean with a lot of top end. I usually like bright amps but they are just too much. It doesn't help that I don't understand the knobs..

https://www.ebay.com.au/itm/354057429136?epid=11018833546&hash=item526f77a090:g:egsAAOSwBetduoCR&amdata=enc%3AAQAHAAAA4HKJlVQx7uUaNQIt8AGhA7TBtNdUv29YBnUT9FCBwOVqBppfGQy5AjCNyFU3tVj5WSZIjNTOvKjRG16ctokT6mXr2G6JJYqrPMrm%2BjxLhitv0gmNxP9c9s40xNj9v8M7R14Q%2BFIL3zgdtiZ57NQJOHf%2BNzP3%2FkbFtzOdQ5RGinp69nIe4DA4uxUc%2F2ObpdIW3W7KCGtpwrtdOaHSXWN9w5e4XNt3KPCneqVlmbxPb2%2BpfH6OibzvQ9wMxMTQt%2Fbri7su7LyhJfiY48p0wPAGRpTMaOifYe9K18VqcRU3duHA%7Ctkp%3ABFBM8I3Lk7xh

There are lots of clips on ewtube but they seem to exaggerate the distortion. For want of a better reference it sounds like a really nice fender clean.

Well if we are drifting off topic I have a question if I may. The amp says "class D". I don't know what that means. Normally a SS amp is less loud into 16 ohms than 8 then 4. This seems not to be the case. I am running it into a 4x12 (8 ohms) wired as 2x2x12 at 16 ohms. Plug in one and flat out it's about right for practice. Plug in both pairs in parallel it should be seeing 8 ohms but there is no discernible increase in volume. I don't understand this. The speakers are chinese celestions.

As I say I've a second coming. With the GT8 and the 2x2x12 it should give some pleasant stereo chorus etc sounds if I want to play with that.


Tassieviking

Guzzies3, have you considered trying to build some of BajaMans Pre-Amp pedals from https://www.freestompboxes.org ?
Some of those can work well in front of an amp I believe.
He has made Amp sims for several different amps as well as speaker sims etc.
They all have vero board layouts for them.
I made up some of them as PCB's but I havent had time to make any yet.

As far as hijacking a thread goes, I don't think Joecool85 minds it happening, at least I hope he doesn't.
As long as it is in a friendly manner and it keeps this site as a friendly forum where like-minded people can have a chat and share ideas and stuff.

Michael


There are no stupid questions.
There are only stupid mistakes.

phatt

#26
In answer to Guzzis3 previous Q, Class D  are a switching amplifiers which use a Pulse Width Modulation system.
 They switch so fast that very little heat is generated thanks to mosfet teck, so no need for big heat sinks. 

C0mplikated to ezplain but some info here might help;
https://www.howtogeek.com/792135/what-is-a-class-d-amplifier-and-what-are-they-useful-for/

The Hotone circuit tricks, after a little bit of analog at input the rest is most likely all done in the digital realm using IR's  (Google *Impulse Response* for clues on that)
Hence each one is programed with a different flavor. ALL the shape and grit is done in the digital chip while the D class output would run clean.

The one I liked most was the "Mojo Diamond" gives a good balance between clean and drive but I've only heard them on the tube.
I'd be waiting till they realise they can make a unit with 4 or more different modes in the one unit but the Diamond would work well with my existing pedal setup.
hope that helps, Phil.

joecool85

I don't mind as long as the topic goes back to the original - I'm very excited about this 12w Marshall!

The Hotone Nano's sound neat, but I also have only heard them on the Tube.  Any time more good-sounding SS gear is out there, it's a good thing.  It gets people to play, and with modern gear.
Life is what you make it.
Still rockin' the Dean Markley K-20X
thatraymond.com

guzzis3

Thank you phatt. Does this trickery explain why it's as loud into 16 ohms as 8 ? I just assumed that as you loaded the outpput of the transistors it's decrease power ?

I wasn't interested in distortion, I just wanted something for practise. If I wanted singing distortion in a SS amp I'd build a Lead 12. (see what I did there?)

Hotone have built a floor mount amp with 2 of the models built in. The one I would buy is the Britwind which combines a plexi and AC30 in a 70W package, but they are far too expensive for what they are..

https://www.ebay.com.au/itm/234080413858?epid=3049063806&hash=item368047a8a2:g:nTkAAOSw1T1cAAcz&amdata=enc%3AAQAHAAAAoDwDsL5qWEAqWy%2BJFDrTazBfqLcnXCktk7k87uz%2F9%2BJbxkVpC0AAWRsGFyqkVRuk217VbCghjYJx3D6PJnC%2FNGj%2FK0rzT6OaziCXKqVpurB7aMFa4r4K9vL%2BTe5nXWDvpv4rL2v%2FwEn1uDpgaD8KEiRj%2B1Lpvyb%2FAXgcGmAJcIadN1ETjwXdkk3xshg1%2Ba4kdV2iKERXGTQJ2CX96CN494c%3D%7Ctkp%3ABk9SR9Crroi-YQ

As I say I can knock together a valve amp in some hours mostly from stuff I have laying around, but that was never the problem I was trying to solve.

Anyway have fun!

phatt

#29
Quote from here;
https://www.soundonsound.com/techniques/what-class-d-amplification

Under, The limitations of Class D
(near the bottom of page)

"Thirdly — not finally, but enough for now — a Class-D amplifier has a **relatively poor damping factor.** The damping factor is the ratio of the impedance of the loudspeaker to the output impedance of the amplifier (it's a little more complex than that, but let's not get bogged down with details). In simple terms, it's a measure of how well the amplifier can control the movement of the diaphragm of the loudspeaker. A good amplifier doesn't just give it a push and hope for the best; it senses where the diaphragm is from moment to moment and controls its position. To do that, a high damping factor is desirable, and, as mentioned above, a simple Class-D amplifier has a low damping factor."

I think of this much like a Valve Amp where the same power output is delivered to  4,8 or 16 ohm speakers partly because most Valve amps have *Low damping factor*.

So even if you drive an 8 ohm speaker from the 4 ohm tap the power is much the same but freq suffers a little.

Better minds may explain this better but there is obviously a connection.
Phil.