Need Tripath TA0104A chip

[James F.]

Apologies in advance for the cross-post. I posted this to the
"Chip Amp" forum earlier before noticing the existence of a
"Class D" forum, which is probably a more appropriate place
for my question.

I bought a Carver Pro ZR-1600 on eBay, in "as is" condition,
and sure enough, when the amp got to me the right channel was
out.

OK, so I'm willing to cough up the money to get the amp fixed.
I contacted Test Point, Inc., of Forest Hill MD, an outfit that
Google retrieved as a repairer of Carver Pro equipment.
I e-mailed their service department, and they replied that the
amp "should be" repairable, so I downloaded and filled out
their service-request form, and sent it, the amp, and a check
for $75 (their non-refundable estimate fee) to Test Point.

Got an e-mail today with the notation "Unit cannot be repaired.
Unit has a defective audio power amp IC and that part is
no longer available for purchase."

The "defective audio power amp IC" is presumably the Tripath
chip itself -- a TA0104A, if information on the Web is correct.

I going to propose to Test Point that they hold the amp and
let me try to find, and send to them, a TA0104A chip that
they can then use to repair the amp.

I am aware of Tripath's financial woes -- the fact that they
declared bankruptcy and were subsequently acquired by Cirrus Logic.

I am a little surprised, though, that an amplifier that was
current a couple of years ago is now being declared "unrepairable".

Can anybody suggest a source for this part?

Thanks!

[luka]

Hi

I think you could use ta105a or tda2500 too instead of ta104a

[theAnonymous1]

Well, they wouldn't exactly work as "drop in" replacements. They would need the external over and under voltage resistor network added to "emulate" the TA0104A.

[James F.]

> [T]hey wouldn't exactly work as "drop in" replacements. They would need the
> external over and under voltage resistor network added to "emulate" the TA0104A.

Yes.

A reply I got in the "Chip Amp" forum pointed me to
http://www.profusionplc.com/products/RA-0105.html

This module is described as being "pin compatible with Tripath's
TA0102/3/4/5".

The data sheet claims
"The feedback and voltage range of the. . . RA-0105 can be configured externally
unlike previous Tripath modules such as TA0104A. Thus, the. . . RA-0105 [is]
capable of emulating Tripath’s previous series of TA0102A, TA0103A, and TA0104A
amplifier drivers with the addition of a small number of external components."

Would a technician at a place like Test Point, do you think, be able to
figure out from the data sheets how to add the "small number of external
components", or would this likely be considered to constitute "design work"
and be beyond the scope of a normal repair?

(I've sent an e-mail to Profusion asking if this module is still available --
it'll cost me $133 plus shipping -- but I haven't yet asked Test Point
whether they'd be able to use it.)

[theAnonymous1]

I highly doubt they will want to be involved with any sort of modification to the circuit. The liability isn't worth their trouble.

If you decide to purchase a RA-0105 (and if they have them available), let me know. I need to purchase a RA-2500 and it would be nice to split the $49 shipping charge.

The RA-2500 can also be used if the RA-0105 is not available. The RA-2500 has full-wave over-current detection abilities, but this requires two additional circuits and is not necessary. Using it in a circuit that previously held one of the earlier ICs should automatically enable the half-wave over-current sensing.

EDIT: I just noticed there are two identical threads here. Maybe a moderator can combine them.

[thomaseliot]

I'm afraid it needs "design work".

The external components are connected to pins 37 and 38 of RA0105A, while these pins are "not connected" to any circuit in the original TA0104A chip.

You would add the voltage sensing circuit with a small external board.

[James F.]

> I'm afraid it needs "design work".

Yes, I suspect I'll either have to locate a drop-in
replacement, i.e. a TA0104A, or just give up.

It's sobering that an amp could go from "brand new"
to "unrepairable" in just a couple of years.

And folks were worried 30 years ago about **tube**
amps becoming unfixable!

Turns out ElectroSpec claims to have 52,838 TA0104As in
stock. Minimum order is $250, and it's not clear whether
they'll deal with a consumer. But I've sent them an "RFQ".

There's also an outfit called "Rodin Audio" that seems to have
inherited what's left of Phoenix Gold, Carver, and AudioSource.
http://www.rodinaudio.com/

I've sent them e-mail too.

[James F.]

Hallelujah!

I got an answer from Rodin Audio:

The TA104 IC is available from Carver. They are $42.32 each +
postage/handling. We also provide repair services. If you
wish to send the unit in, call 800-950-1449 to request an
RA number. If you wish to order parts, use X314.

Best regards,

Phil Koehn
Product Service
Customer Support/Technical Assistance
Rodin
Phoenix Gold/Audiosource/Carver
9200 N. Decatur St.
Portland, OR 97203
(503) 978-3314 (Direct)
(800) 950-1449 X314 (Toll Free)
(503) 978-3326 (Fax)
www.rodinaudio.com
www.phoenixgold.com
www.audiosource.net

[theAnonymous1]

Nice.

I think I will try ordering one for myself. I have three AudioSource AMP7T amps that also use the TA0104A and it would be nice to have an extra IC "just in case".

[luka]

Hi

Only 42$? That is pretty cheap for this kind of chip