Frankenplexi 2 is complete.

[guitardude57]

Here are a few pics of my latest build.  It was a bunch of fun, and the cabinet was quite a bit of work.
Doug made the turret board for me, and I added a few more turrets to make it do what I needed.

Basically, is the 1986/87 circuits combined, and switchable with a couple of switches.
6V6 power, a repurposed Carvin Chassis, and older Organ and HiFi trannies.
I have been using it at my weekly Wed jam in Austin, and sounds pretty darn good.

Will put up some sound clips when I get the chance.

[sluckey]

Nice job!

[guitardude57]

Nice job!

Thanks man!

[Willabe]

Looks good!   

[kagliostro]

Nice job and cool cabinet 


Franco

[eleventeen]

Very nice work, clean understated cabinet.


I'll bet the (comparatively) oversized output tranny is a big help. 6V6 tubes have a wonderful sound but it is very rare (in my experience) that they are not married to an undersized output tranny. I got a Lowrey organ amp a while ago that uses 7591's...the output trannys are not enclosed with metal end-bells (like yours is) but they are or would be quite large for 6V6 outputs. That project awaits.

[guitardude57]

The origin of the OT was... one of the 2 in a stereo 7189 powered Pioneer tube amp.
The other is in Frankenplexi, (the original Pioneer Chassis) where the amp was stripped down for a test bed amp.
It had been many different circuits, and lastly the Marshall 86 circuit, where it has been for 6 years.

The 1962 RCA 6V6's were installed into it...in a couple of the vacant holes, that were step drilled for octal sockets.
This way the amp could use the 7189 tubes (cat biased) or the 6V6 tubes (cat biased).
I liked the way the 6V6's sounded, and used my strange metal box for easily, a hundred gigs.
The old RCA's finally died, as I was completing the new amp.


The trannies are a Tamura brand from Japan, (where the original Pioneer Integated Amp was made)
and actually has secondaries in 4-8-16R.

The new amp will get plenty of use, and I hope to inspire some folks to want me to build them one.
I am looking around to find someone to repro these OT's, as I am preferring a HIFI tranny for these amps.

[eleventeen]

You'll probably do just fine without excess cost or anxiety simply installing a tranny made for dual 6>L<6 use (35-45 watts) for your 20 watt 6>V<6 application. Simple as that. I believe the plate impedances are the same. That *is* quite the oversize tranny for 7189 use.

[guitardude57]

8K is typical for 6V6.  10K is OK.
6L6's like 3K8...

Of course if one is going for an intentional mismatch, anything is fair game.