Which Amp?

[snowman_al]

This is a confusing thread?
Shane says he had replaced the coupling caps with Soniqs and you can just see them in the picture and the Jensens are not in the coupling cap locations.

So what are the Jensens doing? As the electrolytic cathode bypass caps are still on the board you have to assume they are in parallel with them?
Why they are needed though is another matter (and across the 270Ω cathode resistor any leakage will be irrelevant).

Alan

[Richard]

The Jensens are in the coupling cap positions Al and are correct 0.22uF 400V.

C11 and the location box for it is printed on the pcb in Martin's picture,

https://i.postimg.cc/C5WcQhkP/kel84-inside.jpg

The Jensens are just very large and cover much of the locations. The original caps were smaller orange drop polyesters seen in WD's picture,

http://www.world-designs.co.uk/revie...%20gallery.htm

The large black caps on extended leads look to be C4/5 moved to allow the motorised vol control to be fitted.

The cathode resistor bypass caps are the 4 same-sized electrolytics with K on their silver end of cans.

[snowman_al]

Thanks for the clarification Richard.
Yes up to speed now.
The Soniqs are just C4 and 5 and the Jensens are the 'coupling caps' C8, 8, 10 and 11 as described. In which case they would best be replaced asap.

Confusion was due to the change in location from the original PWB to the V3.4
and lack of coffee...



Apologies, Alan

[Shane]

Originally Posted by Richard

The Jensens are in the coupling cap positions Al and are correct 0.22uF 400V.

C11 and the location box for it is printed on the pcb in Martin's picture,

https://i.postimg.cc/C5WcQhkP/kel84-inside.jpg

The Jensens are just very large and cover much of the locations. The original caps were smaller orange drop polyesters seen in WD's picture,

http://www.world-designs.co.uk/revie...%20gallery.htm

The large black caps on extended leads look to be C4/5 moved to allow the motorised vol control to be fitted.

The cathode resistor bypass caps are the 4 same-sized electrolytics with K on their silver end of cans.

Apologies to all, it’s a couple of years since I delved inside this thing. Richard is correct!

[Shane]

Originally Posted by A Stuart

Difficult to tell from photo, and not familiar with the amp, but does something not look right with the black wire? (selected from picture) It looks as if it is floating free.

The remote volume control has a small dc motor attached to the back of it. To minimise the risk of accidental short-circuits I enclosed the whole thing in heat-shrink which completely hides the motor in this photo except for the wiring tag to which that black wire is attached.

[Pingushome]

Thanks to everyone who contributed it’s been a great help. I think I’ve got a good idea now of how to proceed. The description of the amps performances (sound characteristics) were particularly useful.
Must admit the kel84 iupstairs I find more engaging than the quads atm.
Is there anyone who can email me a build manual copy if Mathew allows it?
The PIO caps will be changed soon but for now Shane’s amp will be left unmolested. I assume the std Jenson pio will be ok or is it really worth the extra to get the copper foil ones?
No doubt I’ll be looking for more nuggets of info when it comes to the kit/kel 88.
(Especial if I can run two monoblocked.) just a thought hmm

Martin

[Greg.]

It was the copper foil PIO’s I fitted in Intenso’s KeL84 to great success. I was sceptical at the time, but after listening, I was convinced of their benefit to the sound.

PM me your email address and I’ll forward documents to you.

[colin.hepburn]

Hi Martin
Yep if Mathew allows it for you then send Greg a PM see link below he should be able to sort you out with what you need
Scrub that Gregs beat me to it see above post
Hope that helps you
Colin

[Pingushome]

Originally Posted by Greg.

It was the copper foil PIO’s I fitted in Intenso’s KeL84 to great success. I was sceptical at the time, but after listening, I was convinced of their benefit to the sound.

PM me your email address and I’ll forward documents to you.

Ha ha Greg you always go for quality over price
I’ve just emailed Mathew to get permission
Thanks
Martin

[Pingushome]

Thanks to every one for the advise and help.

I have now bought an old KIt88 (cica2000) part completed which came with a spare pcb and chassis, I’ll get round to sorting that in a few weeks. Hopefully that’ll then be my main amp. Probably upgraded with POI copper foil caps and decent pot plus any other suggestions the knowledgable forum members make. As I have a spare pcb and chassis for the Kit88 has anyone any ideas about output TXs or the mains TX, I had the whimsical idea of eventually using two amps in monoblock mode. That’s for another day tho.

As to Shane’s kel 84 HiFi Collective are out of the POI Jensen caps at the moment so replacing them will have to wait a bit as I’d like to replace like with like rather than upgrade to the copper foil ones a for now. It’s still a brilliant piece of kit as it stands.

Martin