2061x from the top

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srbenefield
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2061x from the top

Post by srbenefield »

Can anyone steer me in the right direction? Looking for a layout diagram based on the actual Marshall design and wiring diagram 2061X-60-02. Have seen a pic of it on Hoffman that was posted a long time ago but it's hard to read. It was done by someone named Mike and there's an email address but it's not legible. Would like to print it. Also as far as Sozo's are there particular caps along the the signal path that make a really big difference? The original calls out 630v caps almost everywhere. I'm assuming the 500v Sozo's will be sufficient and what I want to use. New to this. Jim
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Re: 2061x from the top

Post by JMPGuitars »

Welcome to the site!

The 2061X is the reissue. The original 20W is the 2061. You can see the 20W schematics (including the 2061X) in our download section here: viewtopic.php?f=25&t=24425

If you want to know what caps to use, look at the voltage in the circuit, and use a higher rating. Over-spec'd is the way to go, but if you need 300V caps, it doesn't matter if you use 500 or 630V caps, you're still in a good place. Review the application before making your choice on voltages.

Thanks,
Josh
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srbenefield
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Re: 2061x from the top

Post by srbenefield »

Yes Josh, working off the 2061x schematic downloaded from here. Turret board is done. Now I'm searching through the thirty or so power transformers I have. Next will be output trans. Thing is this diagram doesn't show voltages. Would like to use some of what I've got. Most are Hammond but I have others. I think all of them are more than adequate VA to handle this. Do you know what the secondary voltage should be?
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Re: 2061x from the top

Post by JMPGuitars »

The trem and bass versions both show voltages, that should get you close enough. Now you got me thinking about making a bass head version. Hmmmmmm... :idea:
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Pressed_Rat
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Re: 2061x from the top

Post by Pressed_Rat »

Voltages? Well, I am building a 2061 clone. Here are my power rail voltages using a Hammond 270DX PT, OT scrounged from a Davis 201A 20W PA amp:

VAC 303
B+ 371
B+1 366
B+2 360
B+3 334
B+4 311

Note I added 1K Screen resistors to each power tube (Sovtek EL84). First power resistor in rail is 47 Ohms, second 470 Ohms, and 10K for the rest. Amp has pretty good drive, sounds great so far.

This build is in a re-purposed DIY 5F6-A chassis. I will put it into a proper chassis at some point, but prior to that I wanted to experiment with the PI variations in the old schematics (1917, 2022, etc.).

Let me know how you are making out with your project.

Ciao,

Kelly
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Re: 2061x from the top

Post by Pressed_Rat »

Here are some photos of my 20 watt clone in a DIY 5F6-A chassis:

The amplifier has a sort of PA derived quality - there isn't much breakup until around 8/10 volume with single coils. Humbuckers bring this on earlier, as does increasing the treble. There is some slight interaction between channels when the inputs are jumpered. Hardly notice it. Takes a boost pedal very well.

I was a little concerned the 270DX wouldn't be able to supply the voltage and current to get a good sound out of this amplifier, but at full volume it really roars. PT gets warm after about 1/2 hour of playing. Sounds much cleaner than the Davis 201A PT, which barely supplied 300 volts at the EL84 plates.

The chassis is definitely ghetto at this point. I have a new chassis for it, but want to try alternative 2022 channel mixing and PI values first.
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