Completed - 5F8A - Four 6V6's

[ToneMerc]

The quad spacing makes real estate a bit tighter. Thus, for the ease of maintenance I'm going to hang the power tube grid stoppers as done by HAD.

TM

[ToneMerc]

More progress here; dog house, support bracket, OT, choke, pots and jacks are mounted.

TM

[Reeltarded]

Incredible. Perfect even.

[ToneMerc]

I'm an idiot; I broke my #1 standing rule which is to mock up parts to check fitment. Thus, for this rule to be followed one needs to have the chassis in hand to do that. This project I jumped the gun and ordered transformers first, then the chassis. Nevermind the fact that High Power Tweed Twin chassis should have been freakin enough clue that the PT needs to have a Twin footprint and not a Bassman.

I'll be ordering the same PT in a Twin footprint tomorrow. Oh well, just another excuse to build another amp....

Ok done minus a PT that fits.

TM

[Reeltarded]

Oh no! hah

Still looks as good as any!

[ToneMerc]

All done with the chassis

Primary input : 124.6 VAC

Filament voltage @ V1: 6.54 VAC

V1: 2.43, 154.6, 151.2

V2: 1.06, 177.2, 298.5

V3: 38.8, 237.7, 226.8

Power tube cathode current: V4= 30.1, V5= 27.6, V6= 28.4, V7= 29.5

Plate voltage = 371
Screen voltage = 368

TM

[ToneMerc]

Burned it in hot for over 2 hours and adjusted bias colder.


Power tube cathode current: V4= 23.1, V5= 20.4, V6= 21.4, V7= 22.7

Plate voltage = 378
Screen voltage = 377

TM

[dcribbs1412]

Congrats TM
lookin good...
has to be fun amp

Darin

[Structo]

So this is a 5F8A Twin power amp?

Did you use a Bassman front end?

[ToneMerc]

So this is a 5F8A Twin power amp?

Did you use a Bassman front end?

Tom, the 5F8A is a 4 output tube (85W) 57-60 Tweed Bassman topology. I set this to run a quad of 6V6's instead. Actually, this also can run a pair of 6l6/EL34 or even a single pair of 6V6 (@ 8 or 16 ohm) with just a rebiasing.

TM

[ToneMerc]

Congrats TM
lookin good...
has to be fun amp

Darin

Thanks Darin

TM

[JGK]

Hi JGK here

Nice build just doing some research and planning a quad 6v6 tweed twin myself. I was just wondering what kind of iron you used you mention the heybower OT which I would assume is a bassman OT. Do you run that through a 4ohm speaker? I was thinking of getting something with multiple taps for a bit more versatility. Also what type of speaker set up did you go with I was thinking perhaps a 15".

Thanks Jim Kaffine

[pompeiisneaks]

Jim,

although it may not be obvious upon first view, this thread is from 2014 by someone that's no longer active on the forums, so it's likely they'll not respond. Someone else around may still know something about it, though, but it may be better to start a new thread with questions in general and link to this one...

~Phil