KEL34 making safe to work on

[John Caswell]

Whatever you do, handle the PCB with extreme care as the tracks will lift at the slightest chance - they certainly do not like repeated component changes.
I also repeat for everyone's benefit, do not under any circumstances bend the component leads hard over against the PCB tracks before soldering as you will curse yourself to hell when you come to exchange/replace a component later on, 5-10º is more than adequate, after all this is Hi Fi not rocket science
Space all high power resistors well away from the PCB especially the EL34 cathode bias resistors and the like.

John

[Greg.]

Originally Posted by willslenco

PS is the KEL34 Upgrade Instruction Manual available?

The upgrade article was published in HiFi World DIY Supplement No 45, June 1999. If you don’t have a copy of this supplement, the article is re-published in the World-Designs Platinum DIY archive CD ROM available from Matthew. See link.

http://www.world-designs.co.uk/cd%20rom.htm

[willslenco]

Originally Posted by John Caswell

Whatever you do, handle the PCB with extreme care as the tracks will lift at the slightest chance - they certainly do not like repeated component changes.
I also repeat for everyone's benefit, do not under any circumstances bend the component leads hard over against the PCB tracks before soldering as you will curse yourself to hell when you come to exchange/replace a component later on, 5-10º is more than adequate, after all this is Hi Fi not rocket science
Space all high power resistors well away from the PCB especially the EL34 cathode bias resistors and the like.

John

Thanks John, wise words and duly noted.

[willslenco]

Originally Posted by Greg.

The upgrade article was published in HiFi World DIY Supplement No 45, June 1999. If you don’t have a copy of this supplement, the article is re-published in the World-Designs Platinum DIY archive CD ROM available from Matthew. See link.

http://www.world-designs.co.uk/cd%20rom.htm

Thanks Greg, yes I have the CD,.

[willslenco]

Board removed and components to be replaced removed, thankfully with not too much damage to tracks.

[John Caswell]

Are people cogenitally incapable of doing tidy work???????

John

[bob orbell]

That's good John considering some of the **** seen on here, do you remember a Pre II converted to CF and Phono II some time ago that the owner said was excellent, it was bloody rubbish and dangerous . Bob

[Richard]

Originally Posted by willslenco

Thanks guys, helpful pointers


I'm tempted to retain the Stargets (C9-C12) and other electrolytic caps for now as they were all part of the upgrade and hopefully are in good shape?

I would definitely change these Will. I think they stopped making Stargets many years ago. If you leave them in you may not even realise if they are working or not, if they are now of low capacity or open cicuit, as the amp would still work but not as well as it should.

[willslenco]

Thanks Richard, I think you're right and I will change them, also I think I will return the rectifier circuits back to original as well.

[Richard]

Hi Will, yes the advice often given here is to build an amp as standard then change something if you can see a reason to.

Some "mods" are electrical and can be tried for logical reason, others are flavourings offering a different mix of musical colourings and presentations.

If any work for the listener then they are worthwhile but most are incremental "icing on the cake".

Popping in the packaged rectifiers will be a neat and reassuring way of restoring the amp. Better diodes and the pi filter do offer a small electrical improvement but it may not be a priority in the system.

Different coupling caps often give a noticeable change in sound despite having similar electrical values. I too tried the Ansars yours has fitted and liked their detailed sound but missed the easy-going sound of the original Rodenstein MKT1813 polyesters. A good alternative are the 0.47uF 630V orange polyesters supplied by Matthew for the WD88VA or the Soniqs SAX,
http://www.world-designs.co.uk/capacitors.htm