6g2 Brownface Princeton build

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StrummersOfThunder
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Re: 6g2 Brownface Princeton build

Post by StrummersOfThunder »

Jay wrote: Thu Nov 14, 2024 4:28 pm
StrummersOfThunder wrote: Thu Nov 14, 2024 2:48 pm Filter caps arrived, so shes officially 'built'. Waiting on valves now.

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Still waiting for a WOF though
Correct
At the moment its an expensive lego set

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Re: 6g2 Brownface Princeton build

Post by Starfire »

So, a Lego set?

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Re: 6g2 Brownface Princeton build

Post by StrummersOfThunder »

Testing testing ...

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Re: 6g2 Brownface Princeton build

Post by StrummersOfThunder »

Well after tackling a couple of inevitable silly wiring errors, I got her up and running.
Im really happy. The grounding scheme has worked very well and therefore has a very low noise floor, great for home/recording use.
The trem is great (ill have to get a clip of that too).

This clip (except for the very end ) is without any boost/drive. The amp is on 4 and thru an attenuator on 3/4. Im using the vibrolux (more on that later) as a cab. Jensen jet 12"

Its only a quick iphone recording. I may set up the mic etc and do a proper recording tomorrow.


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Re: 6g2 Brownface Princeton build

Post by StrummersOfThunder »

Neck pickup JM, clean jazz tones



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Re: 6g2 Brownface Princeton build

Post by jeremyb »

Love it!
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Re: 6g2 Brownface Princeton build

Post by MikeC »

It's got a naturally airy reverby tone in my headphones. Sounds great.
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Re: 6g2 Brownface Princeton build

Post by Slowy »

StrummersOfThunder wrote: Tue Nov 26, 2024 4:46 pm Well after tackling a couple of inevitable silly wiring errors, I got her up and running.
Im really happy. The grounding scheme has worked very well and therefore has a very low noise floor, great for home/recording use.
The trem is great (ill have to get a clip of that too).

This clip (except for the very end ) is without any boost/drive. The amp is on 4 and thru an attenuator on 3/4. Im using the vibrolux (more on that later) as a cab. Jensen jet 12"

Its only a quick iphone recording. I may set up the mic etc and do a proper recording tomorrow.

That's fabulous; fat and rich as a triple cheese lasagne! A good Telecaster would be delighted with that amp.
Very well done Sir!! :clap: :clap:
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Re: 6g2 Brownface Princeton build

Post by robthemac »

I think your microphones are in my garage.
Jops wrote: Sun Sep 18, 2022 7:46 am Spring is the comic sans of reverbs anyway.

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Re: 6g2 Brownface Princeton build

Post by StrummersOfThunder »

robthemac wrote: Tue Nov 26, 2024 7:13 pm I think your microphones are in my garage.
Know it all

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Re: 6g2 Brownface Princeton build

Post by StrummersOfThunder »

MikeC wrote: Tue Nov 26, 2024 5:45 pm It's got a naturally airy reverby tone in my headphones. Sounds great.
That may have been a little reverb pedal…
But i agree, it has a sort of transparency to the compression that black face circuits maybe lack.
Breaks up very early even with single coils.
I like this circuit a lot

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Re: 6g2 Brownface Princeton build

Post by MikeC »

Ahha, well at least I know my ears are OK!
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Re: 6g2 Brownface Princeton build

Post by Jay »

Please post the final circuit you ended up building

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Re: 6g2 Brownface Princeton build

Post by StrummersOfThunder »

Jay wrote: Wed Nov 27, 2024 10:43 am Please post the final circuit you ended up building
It’s basically the stock 6g2 but for:
individual filter caps, rectifier diodes, 6V6 grid stopper and screen resistors, 1/4 tremolo pedal jack and Hoffman modified Princeton bias circuit, bias testing points, changed the stock tremolo caps slightly to get a slower deeper trem (that’s the ugly brown polyester cap in there … :wave: )
Seperated the ground points to a buss from the original cap can to preamp / power nodes etc
And then spent a bit of cork sniffy components , shielded cable, impedance switch

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Re: 6g2 Brownface Princeton build

Post by StrummersOfThunder »

Any of the gurus happy to check if my voltages are looking ok? There are certainly some variances to the OG schematic but from what I read that is to be expected and teh fender numbers arent gospel.

So far as biasing goes:
PC PV PD
6V6 1 - 21.6mA 308.7v 6.66w

6V6 2 23.8mA 308.2v 7.33

70% PD for 6V6 = 12 x 0.7 = 8.4

So one tube is at 55% and the other at 61% , so biased on the cool side. But safely so Im guessing?

In terms of the other voltages the only thing significantly out of spec is the pins 1 and 6 on V1 12ax7. Fender schematic shows 135v but im getting 200v.

But the voltages on pins 3 and 8 of that tube seem to be close to correct (calls for 1.5v and im getting 1.3-1.4).

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