Tweaking an 80s preamp

[changer]

One more question:

Just go for low cost but check sizing.

What is acceptable "low cost" for you in this case? Perhaps I am more on a budget than others and I could misunderstand. Eight CSA 4,7mF caps cost me about 150 euro, which is almost the preamp's price. I would like to go cheaper but only if it is acceptable. Any suggetions?

Also, could it be that I made a mistake: 470nF is 0,47µF. Accordingly, it would be 0,47µF capacitors at linestage input, and 4,7µF capacitors ib phonostage input and linestage output.

[Clive]

First of all, thank you for the translation on the conclusions..very interesting.

My post about capacitor types at the top of page 2 is full of typos...

I used a mix of JB Capacitors - JFX series and Clarity Cap SA series. The large phono stage ones are 0,47µF (I think they are from the poor photo...) - in the UK they are £3.20 each. The JFX 4,7µF are £2 each.

There's no magic with my choices. You could for example use Solen polypropylene capacitors. Also film capacitor will be much better than the originals.

[Clive]

I've checked the order I sent to HiFi Collective.

4 x 0,47µF Clarity Cap SA
4 x 4,7µF JP Capacitor JFX
4 x 1µF JP Capacitor JFX

There must be 2 x 1µF which I didn't take photos of.

[Clive]

Maybe two of the 1µF were for a different project, I really don't recall. Sorry...

[changer]

Thanks for the clarification. According to Humble Homemade Hifi, the MKP caps you chose should be close to the original tonal balance of the replaced electrolytics:

"In some cases the 'flat' sound can work well, for example if you just want to keep things tame or if you are replacing some old electrolytics or MKT's and don't want to shift the tonal balance too much."

http://www.humblehomemadehifi.com/Cap.html

What do you think about the signal-to-noise ratio of the two amps playing together?

Section C, section B is power amp only.


The preamp, right column only.

[changer]

I could buy the poweramp, I only have the preamp now. But the one I found at a good price has a yellowish shimmer in the interior. Is it from smoking or normal aging? Should I stay away from it? The outside looks much better, pretty good actually.



The terminals were exchanged, this is why we see non-original cables in the top section.

[Clive]

The yellow might just be the lighting changing the white balance of the photo. Depends on the price...

[changer]

The owner said it is not only the whitebalance, he put the paper for comparison. I can have a look myself on the weekend.

Negotiations before the interior images where shared: 275€ (245£)

[Macca]

That's a cheap price, I paid £350 for mine. It's a good power amp, easily worth the money.

[Clive]

Yes the price is good. A lot of the yellowing looks to be on the internal speaker cables. If these were not yellow the overall effect would be much more normal. Cables can age like that or maybe they had some colour originally.

Re the noise figures...all I can say is that I have no noise issues when the pre/power is plugged into my 100db sensitivity speakers.