[iluvtubes]

Is anyone familiar with the McIntosh MAC-1500, a mid-1960's hybrid receiver, from a technical point of view? I'm trying to determine the value of two burned resistors in the power supply, and no schematic covers it.
Thanks!

[[email protected]]

On Dec 23, 2:20*pm, iluvtubes
wrote:
Is anyone familiar with the McIntosh MAC-1500, a mid-1960's hybrid
receiver, from a technical point of view? I'm trying to determine the
value of two burned resistors in the power supply, and no schematic
covers it.
Thanks!

--
iluvtubes
The schematic diagrams are posted on various websites. Free.

[Ian Iveson[_2_]]

On Dec 23, 7:20*pm, iluvtubes
wrote:
Is anyone familiar with the McIntosh MAC-1500, a mid-1960's hybrid
receiver, from a technical point of view? I'm trying to determine the
value of two burned resistors in the power supply, and no schematic
covers it.
Thanks!

--
iluvtubes

http://www.berners.ch/McIntosh/Downl...AC1500_ser.pdf

includes ps schematic afaics

describe how yours differs, and someone may be able to help

ian

[iluvtubes]

Originally Posted by

On Dec 23, 2:20*pm, iluvtubes
wrote:
Is anyone familiar with the McIntosh MAC-1500, a mid-1960's hybrid
receiver, from a technical point of view? I'm trying to determine the
value of two burned resistors in the power supply, and no schematic
covers it.
Thanks!

--
iluvtubes
The schematic diagrams are posted on various websites. Free.

Thank you! Yes, I do have a copy of the schematic you're referring to. But it only covers the early production models and does not reflect the changes made in later units.

[[email protected]]

On Dec 24, 12:06*pm, iluvtubes
wrote:
;949434 Wrote:

On Dec 23, 2:20*pm, iluvtubes
wrote:-
Is anyone familiar with the McIntosh MAC-1500, a mid-1960's hybrid
receiver, from a technical point of view? I'm trying to determine the
value of two burned resistors in the power supply, and no schematic
covers it.
Thanks!

--
iluvtubes-
The schematic diagrams are posted on various websites. Free.

Thank you! Yes, I do have a copy of the schematic you're referring to.
But it only covers the early production models and does not reflect the
changes made in later units.

--
iluvtubes

I would send an email to McIntosh. There is also a list of ECNs
available at Pete Millett's site IIRC. It may have been a back change
too.

But don't replace the resistors until you figure out why they burned.
They may have done what they were supposed to do, i.e., act as fuses.
A subber power supply comes in handy here.

[Phil Allison[_3_]]

"Ian Iveson"

http://www.berners.ch/McIntosh/Downl...AC1500_ser.pdf

includes ps schematic afaics


** Did you even look at the schems ?

They are all completely illegible.



.... Phil

[[email protected]]

On Dec 24, 5:37*pm, "Phil Allison" wrote:
"Ian Iveson"

http://www.berners.ch/McIntosh/Downl...AC1500_ser.pdf

includes ps schematic afaics

** Did you even look at the schems ?

* *They are all completely illegible.

... *Phil

Try this one.

http://www.tubebooks.org/file_downlo...ice_manual.pdf

[Ian Iveson[_2_]]

On Dec 26, 12:50*am, wrote:
On Dec 24, 5:37*pm, "Phil Allison" wrote:

"Ian Iveson"

http://www.berners.ch/McIntosh/Downl...AC1500_ser.pdf

Hello Phil, merry christmas. Always nice to know you're still there,
in Australia.

** Did you even look at the schems ?

Not for long. Couldn't be bothered searching for the best example.
Luke warm I know, but positive all the same.

* *They are all completely illegible.

Oh well.

Just suggesting a different approach to asking the question. the
probability of finding someone here who knows the resistor values, or
has a set of the same vintage, is quite small. If the OP isn't able to
discuss the details of the circuit, he won't get anywhere, probably.

Perhaps he could sketch his circuit, and ask what's missing. Like a
christmas quiz. It's been a while since we had one.

*Try this one.

http://www.tubebooks.org/file_downlo...0_service_manu...

Thanks, Phil.

Ian

[iluvtubes]

Originally Posted by

On Dec 24, 5:37*pm, "Phil Allison" wrote:
"Ian Iveson"

http://www.berners.ch/McIntosh/Downl...AC1500_ser.pdf

includes ps schematic afaics

** Did you even look at the schems ?

* *They are all completely illegible.

... *Phil

Try this one.

http://www.tubebooks.org/file_downlo...ice_manual.pdf

I ended up having to spend $25 to buy one from Audio Classics. It's the same one that's all over the Internet, but it was legible.....just barely though.

[iluvtubes]

Originally Posted by Ian Iveson[_2_]

On Dec 26, 12:50*am, wrote:
On Dec 24, 5:37*pm, "Phil Allison" wrote:

"Ian Iveson"

http://www.berners.ch/McIntosh/Downl...AC1500_ser.pdf

Hello Phil, merry christmas. Always nice to know you're still there,
in Australia.

** Did you even look at the schems ?

Not for long. Couldn't be bothered searching for the best example.
Luke warm I know, but positive all the same.

* *They are all completely illegible.

Oh well.

Just suggesting a different approach to asking the question. the
probability of finding someone here who knows the resistor values, or
has a set of the same vintage, is quite small. If the OP isn't able to
discuss the details of the circuit, he won't get anywhere, probably.

Perhaps he could sketch his circuit, and ask what's missing. Like a
christmas quiz. It's been a while since we had one.

*Try this one.

http://www.tubebooks.org/file_downlo...0_service_manu...

Thanks, Phil.

Ian

As far as I can determine, the connection points and circuitry are all the same as the early schematic indicates. All the caps are the same values. The only things different are some of the power resistor values are lower than what the schematic calls for.
In my first post, I might have overstated when I said "burned". Maybe more like discolored, or ran hot, to the point that the color bands have darkened somewhat. If I could just find pictures of another late model MAC-1500, that would solve everything. I came across one online, but unfortunately it was too blurry to make out the resistor values. But it also told me that mine is completely original and untouched, since it had the same resistor layout as mine.