Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: fossilshark on July 14, 2016, 10:21:21 pm
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what is a 6v6 typically rated at for power output, im assuming around 15 watts? if so then would anyone have a circuit for using multiple 6v6's to get 30-40 watts? im going to be using a very high gain preamp using 2 12ax7s.
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Tubes are not just power output as measured in watts...they have or at least are perceived to have certain tonal characteristics. To me: 6V6's have a very round, pleasing sound, though at lowish power. Most people consider EL84's to be very similar to 6V6's but they usually operate at lower voltages so that imparts a certain something to EL84 -fired amps vs a 6V6 one and I like them less than 6V6. A bit choked off, sterile. 6L6's have a clear, airy open sound. KT66's are similar to 6L6 while seeming slightly more powerful. 7591's have a tighter cleaner sound probably better associated with hi-fi, maybe some would call that "sterile" compared to 6L6. These things are subjective, person-to-person but they aren't completely imaginary. 7027s are usually found in Ampegs which are usually considered cleaner amps than Fenders so maybe in that case there is a prejudice created that 7027s are slightly cleaner and tighter than 6L6. This could be true of all of these different types. Zillions of amps were made with 6V6s and EL84's/6BQ5 in the 50's and 60's...both music amps and hi-fi amps.
I myself am not very sensitive to this, I'd rather have amps that used only 1 or two types of tubes if I have multiple amps. But that's not so for everyone.
I've been wanting to build a 4 x 6V6 amp for a while, I think it would be very nice sounding and very versatile esp if one pair of 6V6 could be shut off.
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Read the datasheet.
The "suggested" conditions for a pair of 6V6 are 10W and 14W.
Exceeding suggestions and indeed nominal ratings, some of the Fenders got over 20W from a pair.
Teaming-up simply means paralleling until happy. Twice the number of tubes, half the load, is double the power, 20W-40W.
But can you find the parts? The 14W/pair calls for 8KCT load. Double-up, we want 4KCT load. In fact a 4K OT is a standard part for a 50W 6L6 amp. Note that we are buying 50W of iron for 28W of output.... heavy, costly, but we may gain extended bass power (ah, but do we want that?). The PT could be two DeLuxe PTs, but that is awkward. The 50W 6L6 PT promises more B+ voltage than is maybe wise on 6V6 (but everybody over-volts 6V6).
The sweetest hi-fi I ever met was an old-old Fisher 4*6V6.
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You want to look for a schematic of a Jim Kelley amp. He used 4x6V6 in his designs (still does too but he designs amps for Suhr now.)
One of the amps on my "build bucket list." They sound amazing. Listen to the Bonamassa videos of him playing them. Fantastic.
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Check out the following thread it is for a quad 6v6 Plexi a Marshal style amp.
Quad 6v6 Plexi (http://el34world.com/Forum/index.php?topic=20220.msg212201#msg212201)
You can find also some more info on the Plexi here:
http://sluckeyamps.com/6v6plexi/6v6plexi.pdf (http://sluckeyamps.com/6v6plexi/6v6plexi.pdf)
http://el34world.com/schematics.htm (http://el34world.com/schematics.htm)