TMB build with 1974x Dagnall transformers

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gi097
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TMB build with 1974x Dagnall transformers

Post by gi097 »

Hello all!

I want to prepare my second amp build (the first one was a JTM45). First I wanted to make an identical 1974x clone, but then I discovered the TMB versions, so I am willing to give these a shot since they seem to have MV (I have neighbours :wink:) and some other goodies.

There are tons of TMB versions out there which make me a bit nervous to start building, since I don't know what will be "the best" layout.

I came across a pair of original Dagnall PT/OT's that are being used on the newer 1974x amplifiers, so I bought them. I've also prepared a lot of photo's from the original 1974x and started to get some parts to clone it.

But then for the TMB version I was looking around on the web to find the "newest/latest/best" TMB version and found this layout from 2020 from Valvestorm: https://valvestorm.com/sites/default/fi ... t_revF.pdf. Latest can be found here: https://valvestorm.com/18watt.

My PT differs from the one used in this layout, as the outputs of it are 2 x 275v, 2 x 3.15v, 1 x 6.3v and 3 x 0v.

Now I have these concerns:

- Will my PT voltages work fine with this layout? Or do I have to change some components?
- Is this layout fine or are there better versions out there? The TMB post from the download section here seems to be a bit old as it's dated from 2012.

Note that I am a complete newbie to amplifiers, but I like to build them and learn from it.

Thanks!
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JMPGuitars
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Re: TMB build with 1974x Dagnall transformers

Post by JMPGuitars »

Hi,

Welcome to the site!

The docs on this site are well tested, and trusted. 2012 is fine if that's the circuit you want.

However, I would recommend you look at the Superlite TMB: viewtopic.php?t=24430

That's my favorite simple/single channel TMB variant, and I updated it last a couple years ago.

Thanks,
Josh
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Re: TMB build with 1974x Dagnall transformers

Post by Bieworm »

Josh is right. The SL TMB is a great amp!👍

The TMB too, but you'll be very, very disappointed if you do it for the MV. That is not a MV, but an OD killer. It stays very loud, but only has less overdrive. I don't think it has any fans here on 18W. There are much better options...
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Re: TMB build with 1974x Dagnall transformers

Post by JMPGuitars »

The master volume in the Superlite TMB doesn't kill the distortion, it changes it (I know you were referring to the standard TMB, but I thought I should mention it).

If you crank the master in the SL TMB, you get power tube distortion. If you drop the MV, you can shift into nice preamp distortion from the cascaded pre. It's definitely one of the best sounding/more versatile amp circuits.
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gi097
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Re: TMB build with 1974x Dagnall transformers

Post by gi097 »

Thanks a lot for your replies! The superlite looks promising. I will take a look if I can combine some bits from this circuit in my amplifier. I started acquiring some components to start with it soon.
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