I bought a couple of McIntosh MC-30s from a tech who did some repair work on
them.

He replaced the electrolytics. The multi-can was replaced with a single
caps mounted underneath the chassis; the hole was fitted with a chrome pipe
hole plug and looks attractive.

One of the amps had faulty output stage coupling caps.

Here are my questions . . .

1. Is it better (for nostalgia, valuation, resale, etc.) to locate some
multi-section cans to mount on the top of the chassis?

2. The tube sockets are loose. I plan to drill out the rivets and replace
them with SS hardware. Any suggestions?

3. I'm inclined to replace the old composition resistors as well as the
"bumblebee" caps with modern components. Any pros or cons?

TIA,

Jon

these amps are yours-do whatever you think it's appropriate.
single caps are better than multicaps.
resistor types are in "ear dependent category",same as signal caps.
modern types are usually technically better than older ones.

--
--
.................................................. ........................
Choky
Prodanovic Aleksandar
YU

"don't use force, "don't use force,
use a larger hammer" use a larger tube
- Choky and IST"
- ZM
.................................................. ...........................
"Jon Yaeger" wrote in message
...
I bought a couple of McIntosh MC-30s from a tech who did some repair work
on
them.

He replaced the electrolytics. The multi-can was replaced with a single
caps mounted underneath the chassis; the hole was fitted with a chrome
pipe
hole plug and looks attractive.

One of the amps had faulty output stage coupling caps.

Here are my questions . . .

1. Is it better (for nostalgia, valuation, resale, etc.) to locate some
multi-section cans to mount on the top of the chassis?

2. The tube sockets are loose. I plan to drill out the rivets and
replace
them with SS hardware. Any suggestions?

3. I'm inclined to replace the old composition resistors as well as the
"bumblebee" caps with modern components. Any pros or cons?

TIA,

Jon

Hi Jon,

I rebuilt my MC30s several years ago. I replaced the multi-cans with new
ones which were available at the time. I think Antique Electronics has
some new stock cans that will work fine. There's no problem with
discrete parts under the chassis, but for appearance purposes, I think
they need the cans.

I didn't have any tube socket problems, so I can't help there.

I didn't replace the comp resistors unless they measured more than 10%
or so out of spec. I replaced all the signal caps with orange drops and
they sound great to me.

The only problem I've had since rebuilding my amps is a failure of the
electrolytic cap in the bias circuit.

My $.02.

Regards,

Raymond

Jon Yaeger wrote:

I bought a couple of McIntosh MC-30s from a tech who did some repair work on
them.

He replaced the electrolytics. The multi-can was replaced with a single
caps mounted underneath the chassis; the hole was fitted with a chrome pipe
hole plug and looks attractive.

One of the amps had faulty output stage coupling caps.

Here are my questions . . .

1. Is it better (for nostalgia, valuation, resale, etc.) to locate some
multi-section cans to mount on the top of the chassis?

2. The tube sockets are loose. I plan to drill out the rivets and replace
them with SS hardware. Any suggestions?

3. I'm inclined to replace the old composition resistors as well as the
"bumblebee" caps with modern components. Any pros or cons?

TIA,

Jon

Jon Yaeger wrote:

I bought a couple of McIntosh MC-30s from a tech who did some repair work on
them.

He replaced the electrolytics. The multi-can was replaced with a single
caps mounted underneath the chassis; the hole was fitted with a chrome pipe
hole plug and looks attractive.

One of the amps had faulty output stage coupling caps.

Here are my questions . . .

1. Is it better (for nostalgia, valuation, resale, etc.) to locate some
multi-section cans to mount on the top of the chassis?

Mint condition tube amps bring higher prices.
I have sometimes retained the electro cans after drilling out the internal
contents which were faulty, without denting the aluminium, and mounted the new
caps within,
which were smaller in size.
New Sensor have some multi section electros which look retro.


2. The tube sockets are loose. I plan to drill out the rivets and replace
them with SS hardware. Any suggestions?

Huh? use transistors instead of tubes?
Have you lost the faith too?
I'd drill the rivets, and use nuts and bolts, and leave the tubes there.

3. I'm inclined to replace the old composition resistors as well as the
"bumblebee" caps with modern components. Any pros or cons?

Smaller sized C&R could be replaced with moderns, without a loss in value
if the parts are good quality, like beyshalg 1 watt metal films,
and wima caps, perhaps axial types to resemble whay you remove.
The amp should look beautiful when the bottom cover is removed.
It might be the same old circuit with all its faults, but
it will be original, perfectly functional, and
acceptable anywhere as original, imho.

Patrick Turner.



TIA,

Jon

I owned an MC 30 for many years - it was the bench amp.

It all depends upon the external condition of the amps - if the
chrome and lettering is nearly perfect, you might consider
restoring them for "collectors value" and selling them in an
appropriate venue then picking up some not quite as nice
looking for your own use and pocket the $$ diff... that's one plan.

But assuming you are going to keep them, then it makes no
difference what you do, as long as you like the results.

Imho, this amp works like a champ in general.

If you change the resistors, you will change the sound a bit,
unless you use carbon composition parts to replace the older
parts. That may or may not be what you want to do.

Similarly, changing out the old paper/foil caps for modern
polypropylenes will also yield technically better performance
but alter the sound slightly. Maybe not for the worse.

As far as the PS cap, it makes no difference if the cap is mounted
on top or not - but I'd leave one there for looks even if it is disconnected.
IF you've continued to use one or more sections of the old one,
then I'd change it out or bypass it entirely - it's gonna die soon enough.

The "SS" are STAINLESS STEEL screws, Patrick! Geez....

Sure SS will work, but you might want to look for some bright
cad, nickel or chrome plated brass hardware to better match
the vintage.

Drill the rivets from the bottom.

Find US made surplus sockets or new, not the imported Chinese
ones - they won't look right.

_-_-bear

Jon Yaeger wrote:

I bought a couple of McIntosh MC-30s from a tech who did some repair work on
them.

He replaced the electrolytics. The multi-can was replaced with a single
caps mounted underneath the chassis; the hole was fitted with a chrome pipe
hole plug and looks attractive.

One of the amps had faulty output stage coupling caps.

Here are my questions . . .

1. Is it better (for nostalgia, valuation, resale, etc.) to locate some
multi-section cans to mount on the top of the chassis?

2. The tube sockets are loose. I plan to drill out the rivets and replace
them with SS hardware. Any suggestions?

3. I'm inclined to replace the old composition resistors as well as the
"bumblebee" caps with modern components. Any pros or cons?

TIA,

Jon

--
_-_- BEAR Labs
- Custom Audio Equipment, Cables, Mods, Repairs -
http://www.bearlabs.com