I have a Teac Model 80-8 1/2" open reel machine I have to repair for a
customer. This is the first 1/2", 8-track machine I've worked on and it's
clear I'm going to need a schematic. The main problem is that some channels
are sounding through to others; for example, with a signal connected to
channel 1 only, it sounds over to channel 2 and faintly to channel 3. This
happens even when monitoring the input without a tape loaded, ruling out a
head alignment issue.
Any advice, or especially a schematic, would be appreciated.

"Chris F."

I have a Teac Model 80-8 1/2" open reel machine I have to repair for a
customer. This is the first 1/2", 8-track machine I've worked on and it's
clear I'm going to need a schematic. The main problem is that some
channels are sounding through to others; for example, with a signal
connected to channel 1 only, it sounds over to channel 2 and faintly to
channel 3. This happens even when monitoring the input without a tape
loaded, ruling out a head alignment issue.
Any advice, or especially a schematic, would be appreciated.


** Have you tried shorting the unused inputs while testing ??

This is how the recorder would be used in practice.


..... Phil

On Sat, 22 Jan 2011 18:48:16 -0800, "Chris F."
wrote:

I have a Teac Model 80-8 1/2" open reel machine I have to repair for a
customer. This is the first 1/2", 8-track machine I've worked on and it's
clear I'm going to need a schematic. The main problem is that some channels
are sounding through to others; for example, with a signal connected to
channel 1 only, it sounds over to channel 2 and faintly to channel 3. This
happens even when monitoring the input without a tape loaded, ruling out a
head alignment issue.
Any advice, or especially a schematic, would be appreciated.


You should be able to get the service manual from:

TEAC America inc
7733 Telegraph Road
Montebello, CA 90640


Parts Department:
voice: (323) 727-4840
fax: (323) 727-7632
e-mail:

I do know that they had copies of the manuals for many of their
old to ancient(early 70's) tape machines.
I worked there for a year and a half and they were still repairing
1/4, 1/2, 1 , and larger machines at that time (3 1/2 years ago)

Chris F. wrote:
I have a Teac Model 80-8 1/2" open reel machine I have to
repair for
a customer. This is the first 1/2", 8-track machine I've worked
on
and it's clear I'm going to need a schematic. The main problem
is
that some channels are sounding through to others; for example,
with
a signal connected to channel 1 only, it sounds over to channel
2 and
faintly to channel 3. This happens even when monitoring the
input
without a tape loaded, ruling out a head alignment issue.
Any advice, or especially a schematic, would be appreciated.

http://www.analogrules.com/manuals/tascam.html

Phil Allison wrote:
"Chris F."

I have a Teac Model 80-8 1/2" open reel machine I have to
repair
for a customer. This is the first 1/2", 8-track machine I've
worked
on and it's clear I'm going to need a schematic. The main
problem is
that some channels are sounding through to others; for
example, with
a signal connected to channel 1 only, it sounds over to
channel 2
and faintly to channel 3. This happens even when monitoring
the
input without a tape loaded, ruling out a head alignment
issue.
Any advice, or especially a schematic, would be appreciated.


** Have you tried shorting the unused inputs while testing ??

This is how the recorder would be used in practice.

If that doesn't eliminate the crosstalk, I'd suspect a common
power supply filter in the low-level stages. Perhaps a dried-up
cap.

Pimpom wrote:
Phil Allison wrote:
"Chris F."

I have a Teac Model 80-8 1/2" open reel machine I have to
repair
for a customer. This is the first 1/2", 8-track machine I've
worked
on and it's clear I'm going to need a schematic. The main
problem is
that some channels are sounding through to others; for
example, with
a signal connected to channel 1 only, it sounds over to
channel 2
and faintly to channel 3. This happens even when monitoring
the
input without a tape loaded, ruling out a head alignment
issue.
Any advice, or especially a schematic, would be appreciated.


** Have you tried shorting the unused inputs while testing ??

This is how the recorder would be used in practice.

If that doesn't eliminate the crosstalk, I'd suspect a common
power supply filter in the low-level stages. Perhaps a dried-up
cap.

There's a Teac-specific web site at https://www.daeinconline.com/index.html.
Send them an email and see if they can help with your problem. They might
even have a manual on the bottom shelf..
--
David
dgminala at mediacombb dot net