7199 substitution in Ampegs

[Snapcase]

I read somewhere there are several drop-in mods for Dynaco 70 amp drivers allowing them using more common and easy to find tubes than the scarce 7199. Would those work on Ampeg B25 or Gemini amps? Any idea about were to find those schems? Are this advisable or is Sovtek 7199 good enough and doesn't worth the effort such mod?



Thanks.

[Zoe_N_Iain]

I've seen the Dynaco 'sub' list, too. Don't see a problem with doing the same in an Ampeg or whatever.

FWIW, though, the Sovtek 7199 sounds every bit as good as NOS to my ears, though I only tend to use them as an input stage. There might be a noticeable difference if used midway through the amp, I suppose, but up front they respond exactly the same to a boost or distortion pedal as a NOS one does. Worth trying one, given the reasonable price.

[Snapcase]

Thanks.

Well, the thing is the reverse. I used Sovtek 7199 in driver possition on Ampegs. But I only had the chance with an old and wore Sylvania. I cannot tell the real difference because that amp was full of GEs and Sylvanias. It sounded superb, but don't know how much affected that 7199 to the whole thing. This is why I'm asking.

[TD_Madden]

those Russian 7199s hum like crazy in my Gibsons.

[Amp Kat]

Before the 7199 was a 6AN8 in the Stereo 70 and they can be used with very minor changes. Many opted for the ECF-80 with some surgery but is much cheaper and sounds as good. The Sovtek is a hit or miss tube as they are not selected and you could get a real hummer or you could get a decent one which is why there are so many sparatic reviews of them. IMO the Sylvania and any NOS are the best sounding as with any NOS tube but the price almost triples and that's the reason why is because they are that much better. Take a shot on the Sovtek if you may but don't be surpised if you get a hummer.

[Snapcase]

This might explain why my B25s keep humming a bit after a full recap job.

Any idea about 7199 substitution for Ampegs?

BTW, What Gibson models used 7199?

[Snapcase]

Well, bad news. Sov 7199 has been discontinued. So alternative tubes are starting to be a real need.

http://store.triodestore.com/7199sov.html

What are those minor changes for 6AN8 usage?

[TD_Madden]

tweed Falcon (GA-19RVT)......brown-version went to 6AN8.

[Snapcase]

This might be a possibility

http://home.alphalink.com.au/~cambie/6AN8amp/6AN8_t.htm

[TD_Madden]

Think the Groove Tube Tube Amps Vol 4 has a section describing this change as well as a 6EU7 to 12AX7 rewire.

[Amp Kat]

tweed Falcon (GA-19RVT)......brown-version went to 6AN8.

Those are cool amps TD and sound great with NOS tubes. That's where I found those Black Lafayette tubes I posted about. I did a falcon and have a discovery in right now that needs some serious work but they were excellent amps ! Great tone at low volumes.

Snapcase I'm sure you can find at least 10 Sovtek 7199's right now pretty easily. At least I bought some from CE a couple of weeks ago. How many do you need after-all they last a pretty long time so 5 will most likely outlast you !. You'll have to rewire the pins on the 6AN8 as it's different than the 7199 and may have to make a resistor change. Go to the Sunn Forum and see if their are some schematics for any of the Sunns with the 6AN8 . The S100 I believe is a 6AN8 based PI and it will show you one wired up.

[TD_Madden]

isn't the 6AN8 a "miniature" tube....needs a re-socket, I think.

[stokes]

I tried the Russian 7199's in a couple of my Ampegs,and I agree they sounded okay,but they didnt last very long,so I ended up hunting down some NOS

[TD_Madden]

correction....the later Falcons used a 6C4 (not 6AN8), as I have been informed...(of course, I COULD have just looked!)

Sorry about MY confusion.

[kurisurokku]

Resurrecting this thread, in case anyone searches for it. www.thetubestore.com has good instructions on using a 6U8A tube instead of a 7199. You just have to re-wire the pins, no resistors needed. Here's the link:

http://lib.store.yahoo.net/lib/thetu.../6U8A-7199.pdf

I haven't done this myself so I don't know if it sounds good or not, but wow those 6U8A tubes are waaaay cheaper than 7199's ;-).