Pentodes in the Preamps

[M Fowler]

Yeah that wild inline Buick Super 8 what a car.

[Phil_S]

Phil,
I didn't realize that was your creation man Maybe driving 8 triodes might be the answer

Now that we've successfully hijacked the thread, I can put it back on track by suggesting the Gibson GA-20. I build one of those, modified for a single pentode input, true PTP style, 6SJ7> 6SL7 > 2x 6V6, 5Y3. Everyone should have one of these. It's got a rich bloozy tone to it. Plenty of overdrive to it, but also rich in harmonic content. I think people would kill for one of these if they were in commercial production. The problem is the tubes. Again, I'm using USA made eBait tubes. I'm not sure if current production would sound as good, but it might be worth a try.

[Chappy]

Decko

These schematics might interest you. The Selmer Zodiac 30 uses an EC83 in the first stage which then drives a EF 86 pentode in the second stage. Perhaps the gain of the first stage will allow the second stage pentode to distort. I've noticed that Selmer has done this on a few of their amplifiers. Maybe they were on to something.

The Herzog created by garnet runs a 6v6 output in a SE config. You can attach a speaker to it and it also has a line out which can then be safely fed into another amplifier. this gives you your true output tube amp distortion at line levels. If you like the guitar sound on American Woman then this might be up your alley.

Check it out here
http://www.garnetamps.com/zog_story.htm

Chappy

[Cliff Schecht]

One of my designs used a 6SJ7 pushing a Bluesbreaker style tonestack (single knob) into a 12AU7 gainstage. The output stage was a 6V6/6L6/EL34 switchable between cathode bias (150 and 300 Ohms) and fixed bias or a mix in between. My goal originally was to emulate a the clean to mean sound of a TW and with a gain of ~30,000 from the input to the power stage, it did this pretty decently. The tonestack didn't work out too well though, at least for guitar it just didn't mesh nicely. However, once I hooked this amplifier up to a vintage Jensen PA speaker it quickly became a fantastic sounding harmonica amp that my band uses in the studio with much success.