Advice on Portaflex requested

[scottgrahammpls]

Hi gang, I am not a gearhead, I am a tone seeker. I have 2 questions:

What models of Portaflex amps are the best in terms of tone?

I have been warned about running out of power but I play in small rooms and rarely turn my 150W Marshall solid state amp above 2. Valid concern or not?

Thanks in advance. And yes, I know I am going to have to shell out. I am prepared.

Sincerely,

Scott Graham
Mpls, MN

[txstrat]

I've built two copies of the B-15N after Joe Piazzas "1968" schematic (bass amp).
All I can say is: "Tone of glory" although I haven't heard any of the other Portaflex's.
Since I used a 100w OT in one case and a 60w OT in the other there was enough punch to keep up with our drummer. Don't know if this is the case with an original too. But anyways, you could mike it if necessary.
I just don't think it would be easy to find one. Good luck.

[Bruce / Mission Amps]

I used to play with a bass player using a B-15N and as long as the guitar player used nothing more then a SF Deluxe Reverb, or once in a while his BF Vibrolux, the stage mix was stellar!!

[Robert M. Martinelli]

A couple of years ago I restored a B-15 and converted it to EL34s (7027s are harder to find and more expensive on this side of the pond), and, probably thanks also to its oversized original PT and OT, I think it has enough guts, dynamic etc to keep up with most drummers (unless you play in a death/thrash metal band), so +1 on what Matt and Bruce said, especially about over-sizing the transformers...you won't regret it (IMHO) !

JM2CW

Cheers

Bob

[psychbeat]

I was thinking of repairing a friends B15 so I can borrow it for an upcoming
tour rather than bringing our 71SVT+8x10 cab which is overkill for this
project.

Anyways, I think the OT is blown and I was looking at the prices on those
things.... its a 70s model so I was wondering if you guys know of
a cheaper alternative than the potted original types?

[txstrat]

What about a fitting two 6L6 Fender replacement OT? Say Bassman or the like.
Would be great if you could (while inside the chassis) take some gut shots to post here. I'm eager for detailed pics of the grounding scheme in those amps.

[psychbeat]

gonna pick up the amp in LA
while Im down there for a show
on the 28th. Ill take pics when
I get er cracked open.

Im into the idea of using oversized
fender trannys if they'll fit etc. (bassman 100?)
theres a chance its the PT - the owner
forgot which trans was blown.
I do realize it will hurt the resale value
but right now its just sitting there
gathering dust...

[Tom Phillips]

...Would be great if you could (while inside the chassis) take some gut shots to post here. I'm eager for detailed pics of the grounding scheme in those amps.

Hi Matt,
I had the attached gut shot in my files. This is a 1964 B-15N whit what appears to be all original parts. Hope you can make out the grounding scheme. Unfortunately, I didn't make any grounding notes at the time the amp was in my shop.
Regards,
Tom

[riz]

FWIW, here's a gut shot of my basketcase. It's about a '67, with two 6L6. It's awaiting that special someday... but, hey it was 60 bux!! One of the greatest guitar amps I ever played through was a later model with 7027s. With an old Gretsch archtop it was astonishing.

[tubessence]

B-15-N Picture!

Hey guys, Here is a picture of the bottom of my '57 B-15-N w/ 6L6's & 6SL7's. Jeff

[txstrat]

Wow, great pic. Thanks.
How about the noise level of your amp?

[tubessence]

Wow, great pic. Thanks.
How about the noise level of your amp?

It's very quiet, it's a very sweet amp. Although it is really a '60 B15 according to the circuit diagram on it, the speaker says '57

[txstrat]

Would it be too much if I asked for some more pics from in and outside? Maybe some details.
Thanks.

[tubessence]

Would it be too much if I asked for some more pics from in and outside? Maybe some details.
Thanks.

Not at all, in fact maybe you can help me. The circuit that is glued inside I have not been able to find in Joe Piazza's diagrams. It has a stereo input jack to blend two separate pickups as well as two other input jacks. You can see the inputs in the gut shot. I'll take some more pics and get them posted soon.

[Rob Gee]

FWIW, here's a gut shot of my basketcase. It's about a '67, with two 6L6. It's awaiting that special someday... but, hey it was 60 bux!! One of the greatest guitar amps I ever played through was a later model with 7027s. With an old Gretsch archtop it was astonishing.

Talk about a robust printed circuit board. I'd like to say that my '68 B-25 had such an easily traceable layout. I didn't know the power tube sockets were directly mounted to the board on these versions. Interesting design. I'd like to check an ampeg b15 from that era someday.

-Rob Gee