Marantz PM66 KI tweeks

[canetoad]

If you're going to replace a lot of the components wouldn't it be cheaper to buy an SE and replace the tx with a toroidal version? I'm trying to source a KI and they are a bit thin on the ground. SEs are a lot cheaper too.

 

[nuryev]

PM66KI mods

Amplifier channel successfully rebuilt, and sounding great - thanks to some of the great people on this site who contributed provided information, sources for components and patience.
Thanks diyAudio -you guys are a great bunch

 

[Glenn2]

@Brent:

I converted the phono inputs in my PM66KI to another set of line-level ones (I don't have a turntable). Problem is, because the phono setting on the source selector switch was never used, the contacts on the attached PCB switch are dirty. When I use this position I have to twiddle the knob a bit to get the left channel to come in.

So, can I:
a) get a direct replacement for this switch (i.e., is it a standard alps part or something)? I didn't pay much attention to it when I had the amp apart.
b) can it be opened and cleaned?
c) is there something I can squirt into it that will do the job without endangering the other contacts?

Cheers!

 

[Fidelity Audio]

Hi Glenn

The top clips off the switch, usually switch cleaner and lots of sliding of the switch will sort it out.
While it is in bits you may as well bypass the source direct etc (or have you already done that?)

I had to remove the phono pcb in mine due to the larger heatsinks LOL

Brent

 

[Glenn2]

Thanks for that Brent!
I'll have a go on a wet Sunday soon (probably won't have to wait long...)
Cheers.

 

[Fidelity Audio]

It's that time and a sad time. I'm selling the uber 66KI

It's been my rear channel amp for the last 6 month and to be honest it's a waste there. Not sure how much I want for it but i'm open to sensible offers. It would also have to be local pick up as the two transformers are layed down rather than bolted down.

Brent

 

[Ben Hanke]

Sad news indeed, Brent. I've been following this thread for about 4 years now, and was recently inspired to gradually start following your mods list. I got the Black Gate cap swaps done so far, and I expect I'll probably continue, although the transformer is hard to get without breaking an amp and those Silmics of yours seem pretty unique (you recently recommended Mundorf to me as alternatives). I hope it goes to a good home and you decide to keep the pics and docs up on your site.

 

[triocat]

Hi Bwent

newbie here, read the posting again and again, bought what was a faulty KI66 to find tit sounds great, got it off ebay and watch yours go too, indeed sad, but not for the buyer.

So many questions, TX, cap values, heatsinks from, what first, what next, when, eh?

so will you be running a day course ' getting to know my KI' with tea and biscuits

Super posts

Tc

 

[triocat]

helllloooo?

 

[triocat]

hi kinda new here, been following the 66Ki tweeks and all and thought i would keep a brief here on my upgrades to the 66KI, of course following closely to Rowemeister who has been great help so far.

Bought a 66KI from ebay - said not working but was working fine when i fiddled with the speaker outputs. the sound is good with a good balance of bass and treble with clarity.

so the amp will be used for a full system - CD17, tuner, vinyl and a CC45 multiCD.

so the very first thing i did was look inside, quite sparsh for a large box.

Then without any cost i removed the wire from the RCA board (PV01)to the board with the record and direct control (PS01), I then wired from the Master volume to the RCA board with the 4 core cable that was from the MV to the PS01, using R,Rgnd, L Lgnd, this is simple to do. By missing out the PS01 board the sound has a cleaner route and does sound better, clarity improved. This cable will be changed for better cable here and from MV to power board, using 20AWG jupiter solid copper.

Next smoother caps and bridge rectifier to change, i have some 63000uf/63v BHC caps coming, but i am working out how to install the new diodes, inductors and bleeder resistor within the current board.

Happy soldering.

Tc

 

[triocat]

Schotty power diodes MBR20200,

HIFI collective £5.50
CPC £1.60
both ex VAT

this is for the same make - ON sc

Amazing price difference.

on another subject where can you get 1% silver mica?

Tc

 

[Fidelity Audio]

Yes they certainly are. They probably get them from CPC/Farnel

I get my Silvered Mica from RS - 495-874 (1500pF)

Brent

 

[triocat]

thanks for the tip

Tc

 

[Fidelity Audio]

No problem

Brent

 

[triocat]

After much review, I will be fitting Polystyrene inplace of Mica caps, still 1%.

got them from here AudioCap: The Audio Capacitor Online Shop using, 100, 120 and 150pf.

Tc

 

[SimontY]

Interesting, why?

 

[triocat]

on review they seem to be be better quality than silver mica, still maintaining 1% tolerance though the max temp is 85c i do not expect this to cause a problem.

will advise soon

Tc

 

[Fidelity Audio]

Marantz used polystyrene caps in the 6010KI (same amp). I found they gave a too polite sound but again this is all down to your system setup and how it matches.

Brent

 

[triocat]

this is like making a cake, ingredients! each component could make it sweet, heavy, fall apart - explode?

I have found the sound already very good and i will be installing and testing as i go along keeping notes on each upgrade, indeed, i may not be able/need to do it all.

polite sound would not be a problem as the amp is for Girlfriend in a solid brick cottage and house is solid to the point of harsh.

Tc

 

[Fidelity Audio]

That's the best way to do it. Caps take ages to burn in.

Brent