Anybody ever recap a Mac C-20 preamp? What sounds good?

"Terry" schreef in bericht
news
On Sun, 13 Jul 2003 00:14:18 -0400, Henry Platt
wrote:

Anybody ever recap a Mac C-20 preamp? What sounds good?

Have used AuriCAP, did a C20 on customers request, I personally was
disapointed in the final sound, the original musical quality of the
C20 was gone and it sounded bright and very much like a soid state
preamplifier. Re capping one with modern fast caps is not the answer
for tube McIntosh, rebuild the power supply with good caps and replace
any of the papers that have leakage with Orange Drops .


Terry

www.mcintoshaudio.com

I don't know the C-20 but in general ......

Orange drops are MKP or MKT ......
MKP adds a more sharp tone to the higher frequencies .
MKT is even worse !!!
So I would stick with the original caps if possible / available and replace
the others with Auricaps since they are more neurtal than MKP and MKT .
Hence your old caps are propably less neutral than the Auricaps .
You might find / like some other NOS oil caps also ......
Anyway it's always a mather of taste .......

Ronald .

If you can afford it recap with Jensen Paper-in-Oil caps, or
other Paper-in-Oil types. You are practicaly guarenteed
good results with these often expensive caps.

Whe recapping with modern film caps, a significant amount
of break-in is required which on a C20 may be up to a year
and a half depending on how use use the different preamp
sections.

I would, if possible, start only replacing the main signal caps and
slowly work my way forward down the audio chain towards
the Phono sections. Not all signal caps may need replacement.

Most definetly with can relpace the FP type PSU caps with
the modern reissue types. This is just insurance and also will
dramatically improve the DC voltage distribution. Often the
PSU caps are the first that need replacement. If they become
even the slightest warm to the touch after 1/2 hour, they
are in my bok 'suspect'. Also if the DC voltages appear 'lower'
than expected, these PSY caps may be drawing up to 20 ma
affecting the overall sound of the C20 preamp.

We have worked on 2 of these C20's and both needed 'emergency'
FP cap replacement.

As the previous RAT respondent mentioned, some vintage tube equipment
will 'change' sound after an extensive recap. In my experience, it
sometimes takes month's or years for the sound to mellow-out
with modern Polyester/Polystyrene types, but on occasions
the magic is gone forever!

If on a budget use Illinois Caps MPW types, but sparingly.
These require abuout 80-100 hours to break in properly.
My Dyna PAS3 was so bright after the VTV upgrade kit
that I spent days rolling tubes only to discover 3 month's
down the road that it was the Illinois Caps!

The typical 'lipstick' caps in these McIntoshes (as I refer
to these as they look like lipstick holders with colorful
stripes) have a very nice sound but over the decades
often act partially like resistors affecting the DC distribution
across the circuit(s).

Good luck!

Rich Sherman

Henry Platt wrote in article
...
Anybody ever recap a Mac C-20 preamp? What sounds good?

Not everyone likes the Jenzens , so maybe if you're on this type of budget
the Audio Notes might be better . (the copper coloured ones)

"Rich Sherman" schreef in bericht
news:01c34959$8b7937c0$0a86290c@default...
If you can afford it recap with Jensen Paper-in-Oil caps, or
other Paper-in-Oil types. You are practicaly guarenteed
good results with these often expensive caps.

Whe recapping with modern film caps, a significant amount
of break-in is required which on a C20 may be up to a year
and a half depending on how use use the different preamp
sections.

I would, if possible, start only replacing the main signal caps and
slowly work my way forward down the audio chain towards
the Phono sections. Not all signal caps may need replacement.

Most definetly with can relpace the FP type PSU caps with
the modern reissue types. This is just insurance and also will
dramatically improve the DC voltage distribution. Often the
PSU caps are the first that need replacement. If they become
even the slightest warm to the touch after 1/2 hour, they
are in my bok 'suspect'. Also if the DC voltages appear 'lower'
than expected, these PSY caps may be drawing up to 20 ma
affecting the overall sound of the C20 preamp.

We have worked on 2 of these C20's and both needed 'emergency'
FP cap replacement.

As the previous RAT respondent mentioned, some vintage tube equipment
will 'change' sound after an extensive recap. In my experience, it
sometimes takes month's or years for the sound to mellow-out
with modern Polyester/Polystyrene types, but on occasions
the magic is gone forever!

If on a budget use Illinois Caps MPW types, but sparingly.
These require abuout 80-100 hours to break in properly.
My Dyna PAS3 was so bright after the VTV upgrade kit
that I spent days rolling tubes only to discover 3 month's
down the road that it was the Illinois Caps!

The typical 'lipstick' caps in these McIntoshes (as I refer
to these as they look like lipstick holders with colorful
stripes) have a very nice sound but over the decades
often act partially like resistors affecting the DC distribution
across the circuit(s).

Good luck!

Rich Sherman

Henry Platt wrote in article
...
Anybody ever recap a Mac C-20 preamp? What sounds good?

"Mikkel C. Simonsen" skrev i en meddelelse
...
Ronald wrote:

Not everyone likes the Jenzens , so maybe if you're on this type of
budget
the Audio Notes might be better . (the copper coloured ones)

You do know that the Audio Note caps are Jensens, right?


Not any more. They make their own caps today.

/ Hans

Ronald wrote:

Not everyone likes the Jenzens , so maybe if you're on this type of budget
the Audio Notes might be better . (the copper coloured ones)

You do know that the Audio Note caps are Jensens, right?

Best regards,

Mikkel C. Simonsen

Ronald wrote:

You do know that the Audio Note caps are Jensens, right?

You know you're one step behind , right ??

I do now - I didn't know they had changed suppliers...

Best regards,

Mikkel C. Simonsen

My post sounded a bit rude maybe , I forgot the " ;-))))) "
Hey , we're all never to old to learn .......

"Mikkel C. Simonsen" schreef in bericht
...
Ronald wrote:

You do know that the Audio Note caps are Jensens, right?

You know you're one step behind , right ??

I do now - I didn't know they had changed suppliers...

Best regards,

Mikkel C. Simonsen

In article ,
Henry Platt wrote:

Anybody ever recap a Mac C-20 preamp? What sounds good?



Well, you have picked about the most difficult preamp around to recap,
due to the sheer quantity of caps. Most recapping will result in much
brighter sound, which will make it sound unbalanced. This is just my
opinion from recapping three of these.

Probably the most logical choice is the Panasonic type polyprops sold by
vendors such as DigiKey, considering the quantity needed.

Don't forget to replace the diodes used for the filament DC supply, as
they, on some production runs, have a tendency to fail, taking the
transformer with them.

Gene McCluney