Transformers

[Tfultz]

I have built 2 18 watt TMB’s. Same layout. Same caps. Same resistors. But different PT and OT in each amp. The heyboer is way louder than the classic tone. Is this normal?

[crgfrench]

Which specific models of Heyboer and Classictone did you use?

And same speaker I assume?

[AussieTim]

May I ask who,s layout is this and are you happy with the end result

[crgfrench]

May I ask who,s layout is this and are you happy with the end result

That looks like the

"18 Watt TMB (Derived from Richie's schematic) revised June 22, 2004"

from this forum.

[AussieTim]

Ok I waded through all the layouts but somehow missed this one, my bad, has anyone posted audio clips from one

[Tfultz]

Yes it’s Ritchie’s layout from here. The heyboer is from mojotone and classic tone from byoc. Both made for 18 watt specific amps. The Classictone is way softer and mellower in overdrive. Heyboer is loud and raunchy. Classictone is dimed and heyboer is up 1/3 to 1/2 on master.

[Tfultz]

Both cool in their own way. The Classictone is more of a practice amp and heyboer could play any size gig with its loudness and snarl. They are just both very different.

[crgfrench]

Could you tell us the actual model numbers? Both of those firms make several that work in an 18 watter. Mojo carries more than 1, or they have in the past anyhow. I don't know which model(s) byoc carries.

[crgfrench]

Also how do the voltages compare when you measure them?

[Tfultz]

Is there a chart on what points to measure voltages and what the voltages should be? Thanks.

[Tfultz]

Pics of transformers

[Tfultz]

I’m getting from both amps 649-685 ac and 294-325 dc tested at cap and power tubes.

[Daviedawg]

It seems to me that the answer to your question "The heyboer is way louder than the classic tone. Is this normal?" is - no that is not right. Something is stealing your signal and it may not be at the OT itself. Also from your response on another thread about it being softer in tone adds to my thoughts in that direction. The audible differences between OTs should not be nearly so marked. So assuming the Classictone is not faulty, proceed on the assumption that something is wrong and look for faults in the circuit, cold joints or whiskers to ground or wrong spec values esp resistors.

But my first action would be to swap output valves between the amps to see if that has an effect.

Dd

[JMPGuitars]

Is there a chart on what points to measure voltages and what the voltages should be? Thanks.

viewtopic.php?f=25&t=24418

Use the reference charts there.

Telling us the range of voltages for both amps isn't nearly enough information. You need to post the full voltage chart for each amp (a side-by-side comparison would be great). Include pin 2 on the power tubes (should be low mV). Make sure you also include the exact B+ for each amp.

Thanks,
Josh

[Rockinrocket]

Plain and simple. The transformers are different even with the same voltage.

The 360dc (I forget) might be the same between transformer brands but the mA quiescent load are most likely different. Heyboer are usually higher and over spec than classic tone and will make the amp louder and cleaner and wont sag as much under load..

For comparison a Merren JMP 50 makes 430dc at 100mA quiescent load and Hyboers 430dc at 250mA quiescent load.

Two identical amps I built, same parts but they sounded very different, the Heyboer muh louder and I prefer the Merren power transformer build.

Then we might have different metals for the core and lams.. all play a factor in tone.

[Daviedawg]

I agree. There is no doubt that different transformers are designed and perform differently to provide a choice of tones. But in this case Tfultz has described the Heyboer as "way louder", in other words a considerable difference in audio output. Which I would not expect from two transformers designed for the same purpose.

Dd

[Tfultz]

Found issue. V2 pins 8 and 3. Classic tone still more gain. Heyboer definitely more clean and headroom. Both equally loud.

[Tfultz]

Next question. My local guitar and amp tech, who definitely knows his craft, builds amps and guitars for some famous folk mentioned definite quality in transformers. A distant last is the clsssic tones. Heyboer pretty good middle of the road. And mercury being without a doubt worth the expense. Any thoughts of those who have built and compared. I’ve heard power transformer doesn’t effect tone but output does considerably.

[JMPGuitars]

Next question. My local guitar and amp tech, who definitely knows his craft, builds amps and guitars for some famous folk mentioned definite quality in transformers. A distant last is the clsssic tones. Heyboer pretty good middle of the road. And mercury being without a doubt worth the expense. Any thoughts of those who have built and compared. I’ve heard power transformer doesn’t effect tone but output does considerably.

It's all hype. Buy into it or not, is up to you. ClassicTone and Heyboer are both great, and so is Mercury Magnetics, except MM cost much more. Edcor and Hammond also put out great transformers, as long as you know what you're getting. Basically any time a store tells you "good better best" - it's all about the price tag, and nothing else.

Regarding your difference in tone between the amps: you should post your voltages as I mentioned previously. The voltages (especially B+) has a big impact on clean headroom vs. overdrive.

Thanks,
Josh

[Daviedawg]

You should read some of the Valve Wizard published information. (Also a former poster here.) His view on power transformers is that they are very significant in the overall tone of an amp in the way it handles the power. He goes so far as to say that what you hear is the power transformer. In other words both transformers matter in the hunt for specific tone.
Nowadays we are spoilt by the good quality of the equipment and components we buy. Almost anything you buy is of a high standard. It was not always the case. Neither is price always a measure of standard. But especially for the tone a person seeks.
So I guess I am saying that the best way to get what is wanted is to do some research into the gear available. Again we are blessed nowadays by the ready access to such information.

Dd