Tweed Overdrive Special

[surfsup]

This amp sounds very good. I noticed on the other forum there is a schematic that uses the VVR. Does this retain the tone most of the range?

[10thTx]

I built two TOS amps both with Dana Hall's VVR. I liked the results alot. I sold one and kept the other. In fact, every amp that I've installed Dana's VVR in has been a positive experience for me.

I think the VVR does a remarkable job of preserving the tone down to about "3". It still sounds good below "3" but the tone begins to change somewhat below "3", IMO.

I first built one of the TOS amps with PPMIV which I think Geezer prefers
(and he is a much better guitarist & perhaps builder) but I like the VVR more. My experience with home quality recording is that the VVR is a huge help.

With respect, Tubenit

[rsalinger]

EL84's are my favorite tube......I have run the TOS preamp into a 2xEL84 poweramp & it is excellent sounding.
If I built another, it would be with a 4xEL84 power section, with the ability to select between 2x or 4x tubes.
Tuned right, a 2xEL84 amp is REALLY LOUD with plenty of headroom for non-stadium gigs.

G

Hmmm... interesting...

For an el84 build, a 290-0-290 PT would be ideal, then. Correct? Only 2v shy on V2b...

Cheers,
Rob

[M Fowler]

Anyone have some 5879 tubes to sell? RCA or Tungsol or etc.

Mark

[ChrisM]

Anyone have some 5879 tubes to sell? RCA or Tungsol or etc.

Mark

I don't Mark.

But I am getting very interested in them these days.
You building this amp?

[10thTx]

Quite a few of them on flea bay at a reasonable price.

http://www.ebay.com/sch/i.html?_nkw=587 ... m270.l1313

With respect, 10thtx

[mcrracer]

Hey guys my dad says he wanted to build one of these Overdrive specials and never got around to it. He built the board for one and populated it but never finished it. Anybody out there want to finish this amp for him. Send me a PM if you are interested and can do this. We can discuss it further.
Thanks
Phil for my dad Mcrracer

[M Fowler]

Thanks guys I had looked at ebay first but wanted to check here first.

I ended up ordering on ebay. Any thoughts as to dropping the tube rectifier socket and go SS rectification with fixed bias on the TOS?

Mark

[10thTx]

dropping the tube rectifier socket and go SS rectification with fixed bias on the TOS?

I think that would work and sound great. I can't remember who did it, but one of the Hoffman forum guys used fixed bias and likes it.

With respect, 10thtx

[TUBEDUDE]

Has anyone done a demo on youtube? I've never been able to get any of these sound files from the posted links to work.

[10thTx]

Has anyone done a demo on youtube?

Not to my knowledge?

Not sure why the soundclips didn't work for you? If you get a popup that asks if you want the window to close, just click "no". Maybe try it again?

http://www.zshare.net/audio/786814058ef04507/ (DaGeezer)

http://www.soundclick.com/player/single ... i&newref=1

http://www.soundclick.com/player/single ... i&newref=1

With respect, 10thtx

[David Root]

da Geezer, the schematic of your E34L TOS shows V2 as a 12AU7, not a 12AY7. Is that right, or a typo? That ain't much oomph driving the 5879.

I ran TubeCad on both and the 12AY7 looks right, gain is 35 and operating point is centered on the load line, Vp is 126V. 12AU7 looks weird, way off center, current too low for the tube, gain is 15, Vp is 72V.

[10thTx]

Hopefully DaGeezer will see you question and answer it. Until then from his earlier post:

The 12AY7 is my personal preference....any 12A_7 works just fine. A higher gain tube would give more "Fattness" & more available gain in the OD section.

I usually use a 12AY7 or a 5751 in V2.

With respect, 10thtx

[David Root]

Thanx 10thTx. Makes sense.

When you say 12AY7, do you use the 6072 at all? I'm starting a low power tweed Twin build and got two 3-mica 6072 for V1 & V2. They are noticeably quieter than the 2-mica 6072, and much quieter than any of the three 12AY7s I have.

[da Geezer]

da Geezer, the schematic of your E34L TOS shows V2 as a 12AU7, not a 12AY7. Is that right, or a typo? That ain't much oomph driving the 5879.

I ran TubeCad on both and the 12AY7 looks right, gain is 35 and operating point is centered on the load line, Vp is 126V. 12AU7 looks weird, way off center, current too low for the tube, gain is 15, Vp is 72V.

Yes, typo.....I had a 12AY7 in there. As 10thTx stated, 5751 works nicely too, for more grunt.