Chimike

Up for sale is my lightly used GSS  Sumo power amp, 1000w , ( not the Baby Sumo !) , in factory supplied case . Very light , compact , and can be used with pedals

if you don't wish to use a dedicated pre amp. Only selling as I've just bought a Jule M700 to go with my Monique .

Would prefer collection from Worthing , West Sussex , where the amp can be tried and tested .

Thanks,

Mike

My recently built Greenboy 12/6 , and  15/6, although on the 15/6 I had to move the port to the rear

of the cab, and add a false floor to get the "Vox" look ! I still LOVE 15's.

I have to Thank the Basschat members that have helped me here .

Finally had time to remake the power transformer connections , and carry out a test, all seems fine on 240v.

Great to be able to do away with the drop down transformer, on this B15, at least !

Better pic !

Seems these were used on the '61 B15 ,the again on the '64 version, that used Silicon rectification .

Maybe my late '64 valve rectifier amp was built using the early '64 boards that had the "thermister type thing ".

Later B15's did away with that component, so I think I'll do the same. Also, there were two versions of the PT108 mains transformer,

part no 300...- 1 for 117v operation, and part no 300...- 3 for 230v operation. Unfortunately, the circuit diagram

I found on the Ampeg website with that info is a bit smudged, but I think I'm sorted now.

Will try the 230v connection on the transformer, through my Variac, and keep a good eye on the output voltages, JIC.

Many Thanks for the help.

Mike

That circuit diagram is similar to mine, at least, on the mains input and primary side. Seems that the  symbol is an old way of showing Resistors, so you're  probably right as to it's " soft start " function .

I'll measure it !

I'll also get a better picture ,will help to confirm.

Thank you Both.

Not the best photo in the world. It's the silver thing between the pink condenser and the white resistor. It's shown on the circuit diag under the amp,

( B12N AND B15N ) between the on / off switch and the mains fuse. Any help greatly appreciated .

So,

Continued searching, and found a mention of a similar transformer on a '63 B15 on music electronics forum .

Guy named Boroman , in Germany, was recently asking the same question as I have re the Blue and blue white taped off wires.

Conclusion  was that it was indeed a dual voltage transformer. He was advised to remove the death cap ( done that ),

And add a resister into the neon pilot light circuit before making connections for 240v.

Only problem I have now, before I try it ( on a variac ) is that there is a " thing " that I don't recognise in line with one side of the mains,

unsure what it does, or what it's voltage rating is.

Will take photo, and show it to my tech friend , when I next see him

Hi,

So, taped up leads, blue and blue/white show no connections to other leads from Transformer. Measure 4 ohms across leads. This is similar to the

Primary leads , black/white and black  , which measure 3.8 ohms . I'd love to think I have a dual primary transformer, but I'm not willing to risk my

old amp on a guess.

BTW. Have done a cap job, and also fitted the protection diodes to the rectifier ( as you have suggested in the past ). Did the same on my SB12, but lost the bias 

'till I realised I had to move that connection as well !

 Thanks,

I'll do that, and report back.

I'm aiming for correct internal volume inside a visually correct Vox AC30 bass cab, although slightly larger, to get the necessary 30.5 inch dim .

So far , I've drawn the cab with a false wall on one side , but I'm having to move the port slot to the rear of the cab , to accommodate the black panel / gold stripe on the front .

Started drawing up the cab, and realised that maybe all I need is a false wall.

I'm wanting to build a Fearful 15/6 as I have some of the parts already.

However, I need to alter the outside dimensions , a I need to replicate an old Vox cab.

This means I will need to adjust the inner volume back to the 15/6 spec to ensure correct tuning.

Is there a suitable material for this purpose ?

Thanks

Mike

Go For it , I'd Kill for that  !

Can anyone throw any light on the problem I'm having with my Boss OC-3 Super Octave pedal.

Works fine when first plugged in, and switches to selected effect immediately when foot pedal engaged.

However, when foot pedal is pressed again , to come out of effect, no sound initially . Then slowly, the sound returns .

Any Ideas ?

Thanks Mike.

Thanks, but just to confirm, it's the power transformer, not the output transformer I was referring to.

, although I do realise  it may be a replacement, but def a proper, potted, B15 replacement, if so.

I'll check out Psionic Audio JIC.

Hoping I can get some info on my B15 mains transformer. Connections all seem correct, and agree with circuit diag under amp.  Tube rectified, non-pcb version. Amp is run from a step down transformer, and  is working fine,( just need to lower the hum level a tad )

However, there appears to be two additional leads attached to the transformer , blue and blue/white , taped off, and tucked away. Can anyone throw light on why they are there ?

I don't want to guess !

Thanks,

Mike.

Quite typical , in the 60's .

Hiya,

Yes , Still available .

Mike

My Sonic Blue Jazz Bass , close  replica of the Jazz bass I played in the late 

'60s, headstock and all , but mine had dots, not blocks !

Hi Merlin,

Yes, Still available 

Now reaching in to my Acoustic Control corp gear. First up is a very nice mid 70's , all original,  470 amp head . This is the dual channel model , with Lead/Bass and distortion functions. So ideal if you play both bass and 6 string.

UK voltage, comprehensive EQ, channel switching. For sale for £295 if collected from Worthing, West Sussex.

PS  The unfinished Replicab 301 clone is not for sale, and is not included .

Any other pics or details, just ask

Hi Rob,

Real,Real Long shot, but do you still have the Green glow in the dark filament ?

Thanks

Mike.

Was great to meet up with Chris last week, when he picked up an amp and some "black boxes " ( my wife's description ! ) from me. Had an enjoyable chat 'bout bass things , even though we were pushed for time .

 Chris was well organised, and a pleasure to deal with ,communicating well at all times , despite some "logistics" problems which Chris quickly dealt with.

Basschat at it's Best ! Thanks Chris, Enjoy the amp.

Now Sold  Mackie SRM450 v2 PA cabs. Bought from a fellow basschatter many moons ago as backup spares, and in my ownership, only used/needed the once !

Both have covers, which have protected them over time , but the top panel has come unstitched on one . Simple fix , probably ! Other than that, covers are in nice , presentable, condition.

Collection only, please , from West Sussex.

Retired from my Rock n Roll band, so selling my PF-500 Portaflex rig . Amp has been great, very reliable . PF-115 cab has light signs of use , but works fine. PF-210HE 2 x 10 cab is almost like new , as I only used it very occasionally.

All in all, a very versatile setup,  amp can switch between cabs easily if you just need one cab on the gig, as the clip-on tops on the Portaflex cabs are interchangeable. Collection only, please , from West Sussex.