KEL34 making safe to work on

[willslenco]

Originally Posted by Greg.

Not more expensive if you look at the broader picture. DIY repairs as well as being pleasurable are very cheap compared to a dealer or electronics engineers charge. Allows for the purchase of higher quality components from the likes of HiFi Collective, some of which are becoming increasingly difficult to source in small quantities. Furthermore, with Nick Lucas (HFC) being the original WAD employee who probably posted out this kit many years ago, there is a certain satisfaction in putting money into his pocket rather than the big industrial suppliers.

Spot on Greg, it's always enjoyable to resurrect something. And I like to support Nick and the prices are acceptable to me, we need to keep these specialist suppliers in business.

[Richard]

Great thread and pictures thanks Malcolm Did you get it all finished and working ok?

[willslenco]

Originally Posted by Richard

Great thread and pictures thanks Malcolm Did you get it all finished and working ok?

Thanks Richard, yes with the offboard rectifier for the 6AU6 heater supplies it works very nicely indeed, in fact sounds excellent through LS3/5a clones and fed by a highly modified Rega RP3, Ortofon Quintet Blue MC and Audio Detail NV-06 nuvista phono stage (designed, built and modified by Mark of Ming Da UK). Also really good with my Rotel CD11 Tribute and Vortexbox 2.5 streamer with Topping D10s DAC.

Now to strip and rebuild the other KEL34.

[willslenco]

Slight disaster yesterday, there were some marks on the paintwork so I thought I'd clean them off with a bit of IPA - mistake, the paint started coming off :angry: Well I was thinking of eventually stripping this down again and repainting but this has hastened it, so I will overhaul the other KEL34 soon so I can take this one apart again!

So I would like some help regarding painting:

1. What paint do you suggest, reasonably durable and heat resistant?

2. I'm open to suggestions regarding colour?

3. The transformer cases also need refinishing so again what paint and colour?

[Richard]

Hi, well, I'm glad it works well and sounds good, I liked mine very much indeed. The paint is annoying but it clearly isn't up to much. Probably a thin coat of spray can on grey primer judging by the dark splatter marks.

If the paint hasn't rubbed through you could try a gentle polish with T Cut Metallic (that's the finer grade in a silver bottle not the original red bottle).

It will be quite a lengthy job to repaint completely so I wouldn't bother doing all the work to end up with a spray can finish again. Temp isn't a problem (think how hot a car panel gets in the sunshine) but spray paint is generally thin and soft. Hammerite spray is a bit tougher but needs a week tor two to cure afterwards.

Instead, I'd call at a local motorcycle shop and ask who does plating and powder coating locally. They usually know. Take in the chassis for blasting and powder coating (they usually offer a range of colours inc satin black) and the TX bell covers for chroming. Wrap the lams with black tape or strips cut from sticky back plastic film as was done by the likes of Leak or paint black.

[bob orbell]

I agree with Richard on the blasting and powder coating, this is (if done properly) a very good product and comes in many colours, if it is powder coating from original, blasting will not remove it but will need a chemical dip tank, plenty of businesses doing this and with regard to blasting a professional should be consulted because some blasters will distort the case badly, ask first. As for the transformers, I would make or have made a cover to hide them, any good fabrication shop should help it would then look very professional. Bob

[Greg.]

Just to add a little, I personally consider that the finish of the output transformers makes a major contribution to the overall aesthetic appearance of the amp. Untreated edges of the lams can rust, discolour and become unsightly. I have had good results spraying the lam edges with Plasticoat satin black available to buy at B&Q or online. Alternatively, the lams can be wrapped in ordinary black insulating tape and 50mm wide tape is available on eBay. It can easily be trimmed back once applied if it is oversize.

Whilst chrome plated end bells look very good, my experience is that these days plating companies have a minimum job charge which is likely to be not far south of £100, so this can be an expensive option unless you can include the covers as part of a bigger job order. An alternative is to spray paint them gloss black (or your colour of choice provided it matches/blends with the chassis colour) which can look really professional.

[willslenco]

Thanks again guys, a lot of food for thought there, especially helpful regarding the transformers - if I put covers on them would they need to be grounded?

I have now found the existing paintwork is very poor, it appears to be a thin coat metallic paint directly on the metal I will probably repaint myself, I have successfully done turntable top plates in the past, with a good primer, multiple colour coats and clear top coats.

[willslenco]

Found some time yesterday to work on the other KEL34, removed board and stripped out all the caps ready for renewal. Also cleaned the board, was very dusty on top side and also loads of flux both sides. And I found why right channel still had a bit of flutter noise, one of the ECC82 anode resistors I had replaced (from bottom of board without removing board from chassis) did not have continuity with track on one leg.

[bob orbell]

Originally Posted by Greg.

Just to add a little, I personally consider that the finish of the output transformers makes a major contribution to the overall aesthetic appearance of the amp. Untreated edges of the lams can rust, discolour and become unsightly. I have had good results spraying the lam edges with Plasticoat satin black available to buy at B&Q or online. Alternatively, the lams can be wrapped in ordinary black insulating tape and 50mm wide tape is available on eBay. It can easily be trimmed back once applied if it is oversize.

Whilst chrome plated end bells look very good, my experience is that these days plating companies have a minimum job charge which is likely to be not far south of £100, so this can be an expensive option unless you can include the covers as part of a bigger job order. An alternative is to spray paint them gloss black (or your colour of choice provided it matches/blends with the chassis colour) which can look really professional.

When I mentioned covers I did not think of small chrome covers, I was thinking of a cover that totally encloses both transformers as in some Icon Audio amplifiers, myself, I think all exposed transformers look naff. Bob