# Would it be possible to build a 4x6V6 Custom Special YBA-3?



## JC103 (Oct 6, 2007)

Recently picked up another late 60s Traynor YBA-3 Custom Special. Years ago I had a great sounding Pepco 727 (Princeton/Deluxe clone), somehow the YBA-3 preamp reminds me of that old Pepco... So I started thinking, would a 4x6V6 Custom Special sound good for Guitar? I think so. Can the plates on 6V6's be run hot like Pete's approach with the YBA-3 and YBA-1A MKII? Can you get about 30-40w out of a quad of 6V6's?


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## Granny Gremlin (Jun 3, 2016)

This early YBA-3 schem says it's running the 6CA7s with 540V on the plates. The max rating according to this 6CA7 datasheet is 800V; not pushing them too hard., but harder than typical range which seems to be 300-500V from that datasheet.

Max plate voltage on a 6V6 is 315V (datasheet), so you'd need to overhaul the power supply to lower all the voltages (see also screen voltage etc) to even try it. Now there's many Fender models that drive 6V6s well above this rating (Champ is 350V). The most I have heard of is 490V. And you might wanna stick with NOS tubes for that.

If you do do it, should be able to get a nice and dirty 40-60 watter with a quad.


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## sammyr (May 7, 2013)

I think NOS tubes are going to burn up pretty quick at that voltage. I've had good results with JJ 6v6's they're rated for 450-500 volts I believe. I think the orange rockerverb 50 is rated for 50 watts and runs a quartet of 6v6's


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## Budda (May 29, 2007)

Did you get the one at pauls boutique?


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## cboutilier (Jan 12, 2016)

JC103 said:


> Recently picked up another late 60s Traynor YBA-3 Custom Special. Years ago I had a great sounding Pepco 727 (Princeton/Deluxe clone), somehow the YBA-3 preamp reminds me of that old Pepco... So I started thinking, would a 4x6V6 Custom Special sound good for Guitar? I think so. Can the plates on 6V6's be run hot like Pete's approach with the YBA-3 and YBA-1A MKII? Can you get about 30-40w out of a quad of 6V6's?


Tell me more about the 727! I have a 730 which is almost exactly a Princeton Reverb


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## jb welder (Sep 14, 2010)

The early YBA-2 used 6V6. Someone added in their voltages on this schemtic which shows around 450V supply, much less to the screens.
You should be able to get at least 30W out of a quad.


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## cboutilier (Jan 12, 2016)

I've always wanted to do a 4x 6v6 Super Reverb or Vibroverb build.


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## JC103 (Oct 6, 2007)

Budda said:


> Did you get the one at pauls boutique?


Nope, I was lucky to find one locally here in Winnipeg. Which let me tell you does not happen often!


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## JC103 (Oct 6, 2007)

cboutilier said:


> Tell me more about the 727! I have a 730 which is almost exactly a Princeton Reverb


Let me dig through my photos... to this day it was one of the best low powered amps I have ever played! I remember it had a tube rectifier, volume, treble, and bass. 2 x 12AX7 in the preamp and of course 2 x 6V6 in the power section. Tiny transformers, light as a feather, and mustard caps galore!


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## JC103 (Oct 6, 2007)

Also thanks everyone for the info, will ponder it some more. Are 6V6GT's a more robust tube? I'll look into to those Orange amps mentioned.


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## cboutilier (Jan 12, 2016)

JC103 said:


> Let me dig through my photos... to this day it was one of the best low powered amps I have ever played! I remember it had a tube rectifier, volume, treble, and bass. 2 x 12AX7 in the preamp and of course 2 x 6V6 in the power section. Tiny transformers, light as a feather, and mustard caps galore!


That sounds a lot like the 720 too. My 730 has two extra preamp tubes to drive the reverb tank and bias vary tremolo. Mustard caps and ampeg style PECs everywhere.


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