2-channel Fender 6V6?

[Tommy_D]

Hello,

I'm getting started on a Deluxe Reverb variation (single channel, reverb - no trem, normal 6V6 power section).

Then thought that I could consider adding 2 tubes (PT would have enough juice) and build a 5f6-a preamp as a new channel.

Not entirely sure how to combine the 2 channels though:
- LTP: could have done directly into LTP like a DC30 but want to keep the negative feedback so that seems challenging
- Mixing resistors: Deluxe Reverb has these to begin with. I'm not sure how the cathode follower of 5f6-a which is the last stage would react / interact with other channel
- Manually switch channels: not a particularly elegant solution it seems...
- Put the NFB elsewhere.. could have it on last gain stage of Deluxe Reverb preamp. Not sure where it would go into 5f6-a preamp. That would certainly change the tone...

Any views / pointers / existing schematics appreciated!!

Or is that just a silly idea and I should just build a Deluxe Reverb + a Bassman?

Thanks all!

As an intro, I'm a new forum member (although I have been reading posts for a while now). Built a few guitar amps now and want to challenge myself with a more advanced build

[sluckey]

- Mixing resistors: Deluxe Reverb has these to begin with. I'm not sure how the cathode follower of 5f6-a which is the last stage would react / interact with other channel

I'd use two 220K mixing resistors. Don't see any problems.

[Tommy_D]

Ok, thanks

I'm told separately that 3-input LTP actually seems to work as well. Relatively easy to try both

Based on your experience, does having 2 preamps / channels into 1 power section have a negative impact on tone vs. having single channel amps?

[pdf64]

I don’t think you can separate out the power amp and the preamp like that; the whole thing (inc chosen speaker and cab types) is an integrated system.
eg the 5F6A without a presence control ain’t a 5F6A; the treble control would naturally need to be set higher, resulting in a different system response than a lower treble with any degree of presence boost. May be perceived as a hollowed out tone.
Likewise for the high pass filter between pre and power amp of an AB763 deluxe.

[Tommy_D]

You're absolutely right - it won't be a 5f6-a, just a variation. I do plan to have a presence control though!

I was going to build 2 single-channel amps with a relatively similar 6V6 power section - a single channel Deluxe Reverb + a variation of a 5f6-a. Conscious neither will sound exactly like the real thing by design but I'm pretty sure both will sound great. I would save a fair bit of cash by building a 2 channel amp instead.

Most iconic amps arguably have 2 channels so I don't think that's detrimental to the tone in itself. Just unsure about the 5f6-a channel this isn't a 2-channel amp to begin with.

Let me rephrase the question: would the tone of the 5f6-a be affected if I combine the two preamps into one amp vs. building 2 separate amps?

[Stevem]

Are there plans to use this amp to gig with, and if so will it be thru 1-12" which I concider the minimum to gig with or will you be running more?

[Tommy_D]

Hi
No plans to gig it, just home use - will go through a 2x10 cab with NOS AC10-type ELACS (at least for now)
Also why I'm going for 6V6's
thanks!

[10thTx]

Here is something to consider. Just a DRAFT schematic. I've not built this. I've attached an editable SCH schematic CHECK for ERRORS!

You'd use an A/B/Y box for the switching.

With respect, 10thtx

[Tommy_D]

That's pretty much exactly what I'm planning to build! thanks

I'll try both mixing resistors + 3-input LTIP and see what sounds best

[10thTx]

IF you had a PT that is 140ma (or more) and is 300-0-300 using a solid state rectifier, you'd probably get about 420v on the plates. JJ 6V6's can easily handle that OR you could consider 5881's.

[Stevem]

Or JJ brand 7591 tubes which have the same specs ( different pin out ) as 5881s and sound far better when driven hard then any Sovtec 5881 ever willing!

[Tommy_D]

That also an excellent point

Was planning to use this
http://www.classictone.net/40-18028.html
http://www.classictone.net/40-18028.pdf

But does it have enough juice to power all these tubes?
- Rectifier (GZ34 or 5A4GB)
- 2x6V6GT
- 2x12AT7
- 2x12AY7
- 1x12AY7

Otherwise this definitely has all the power one needs but will also sound less "tubey". And the 710V HT is aggressive...
http://www.classictone.net/40-18029.html
http://www.classictone.net/40-18029.pdf

[Stevem]

Seeing as in that schematic shown the OT has a 8 ohm tap, the amp would sound a good amount better if those 4 drivers where rewired to provide a 8 ohm load.

[Tommy_D]

The cab I have is actually 8ohm. I'm planning to use a 4/8/16 ohm OT - 20W Classictone Fender-style

Biggest question to me is does PT have enough power though

[sluckey]

Biggest question to me is does PT have enough power though

yes