Upgrade TA7136P1 in Phono and Tone board

elvi

elvi

Super Member
Its time for my 1st recap project. I selected a rather simple unit; a SA-6800.
Thanks to the members here, the recap list should be a snap. (I have the list for my SA9500, but want to cut my teeth on the simpler amp 1st)
I have yet another surgery coming up, and it should keep me busy for a day or so.. keep the brain busy, the pain goes away..

While I am replacing and reflowing; I want to upgrade the Operation amps. (see.. I did retain something from Tech school..in the 70's..)

The A-6800 uses 4 Ta7136 OPs. one for each channel in the Phono and 2 in the tone.


2 questions:

1st
I want to use a single, single channel OP Amp at each location; and am looking at the Browndog and Surfboard adapters.

I can see the PDF for the surfboard, and see I just need to add a few jumpers.
Does anyone have the DIP to SIP pinout for the BrownDog p/n 060301?

2nd question:

Op amps.

I am considering the TI \ BurrBrown OPA604. (Buck and change at Mouser)
From MarkTheFixer and other posts I see the OPA604 should work.

It looks like it would be happy at +21 -21; with a documented max of 25. (If my research is not flawed)


Pinouts.. (for future use.. my scratchpad..)



Here is what I read from the 6800 schematic

EQ GWF-122 as built. This image is from page 6, and the hand addition is from the schematic on page 15, and verifed as on the actual board.
Phono EQ assembly (GWF-122)



TA7136P pinout:

1. + rail volt comparator
2. + input
3. NFB - input
4. V-
5. + rail voltage comparator
6. output
7. V+



LME49870 \ OPA604 pinout

1. Offset trim 8. Dead pin, NC
2. -in 7. + V rail
3. +in 6. output
4. - V rail 5. Offset trim

Implemented modifications to Phono and Tone Amplification circuit
 

Attachments

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Pin 1 and 5 of the original 7136 can be ignored, and any components connected to these pins removed. The rest of the pins you have for this opamp are correct, but pin #3 may or may not be where the NFB connects...depends on the circuit. It is simply the inverting (the "-") input.

The TA7136P was used a lot, but no one has a drop-in adapter that I know of. Your Brown Dog link is for an adapter using a common 8-pin SIP part, like the NJM4580L. Cimarron Technology will do a custom job, but I don't think you're ready to pony-up the requisite $150 for a pair of 'em. If you want to swap opamps, you'll have to mount your new one on a small bit of perfboard and run wires to the appropriate solder holes where the 7136 was removed.
 
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OK...I got around to looking at the Surfboard. Doable. The OPA604 can take +/-24V supplies, but it isn't your only choice...the Texas Instruments LME49870 can take +/-22V. The supplies to the opamps in the SA-6800 are regulated +/-20.4V, so either will work. The LME49870 will probably have the lowest offset at the opamp output, and you may be able to replace the output coupling caps (C109, C110, C207, C208) with a jumper wire or zero ohm resistor if the resulting offset is lower than about 5mV (may not be possible on the phono, with all that gain, but the tone control is a real possibility for dumping the coupling caps).

The SA-6800 has dropping resistors for the positive supply on each pair of opamps...R123 on the phono amp board (33 ohms) and R280 in the tone control section (100 ohms). These should be replaced with a zero-ohm resistor or a jumper wire.

For the common single opamp pinout, such as the OPA604 or LME49870:

Pin 1 of opamp: Unused
Pin 2 of opamp: Inverting input. Connect to Pin 3 of adapter.
Pin 3 of opamp: Non-inverting input. Connect to Pin 2 of adapter.
Pin 4 of opamp: Negative supply. Connect to Pin 4 of adapter.
Pin 5 of opamp: Unused
Pin 6 of opamp: Output. Connect to Pin 6 of adapter.
Pin 7 of opamp: Positive supply. Connect to Pin 7 of adapter.
Pin 8 of opamp: Unused. Clip off Pin 8 of the adapter.

You can see that Pin 2 and Pin 3 of the opamp and adapter get crossed, which is going to be a bit tricky to connect at the pads of the Surfboard. If you can figure out how to do it...(it'll be some really fine work under a magnifier...something I'd have trouble doing with my middle-aged eyes).
 
"You can see that Pin 2 and Pin 3 of the opamp and adapter get crossed, which is going to be a bit tricky to connect at the pads of the Surfboard. If you can figure out how to do it...(it'll be some really fine work under a magnifier...something I'd have trouble doing with my middle-aged eyes)"

The surfboard will allow me to drill thorough the PWB at pins 2 and 3, and then add my crossing wires on the backside. Easy as cake; but I cheat. I have a stereo scope..


"you may be able to replace the output coupling caps (C109, C110, C207, C208) with a jumper wire or zero ohm resistor if the resulting offset is lower than about 5mV (may not be possible on the phono, with all that gain, but the tone control is a real possibility for dumping the coupling caps)."

I see a note i the application specs (For the 604)

"Applications with noisy or high impedance
power supply lines may require decoupling capacitors
close to the device pins. In most cases, a 1μF tantalum
capacitor at each power supply pin is adequate."

Would it not be a bad idea to add the 1uf as SMD on all 4?

"if the resulting offset is lower than about 5mV"

I assume I am measuring this across the amp section; pins 2 and 6 of the 7136? Would that be a good idea to do before I make any changes?

(Parts BOM being built as I type.. there was no recap list for the SA-6800; so building one from scratch)
 
#1. I hate you.

#2. Most of the time, mfgr's are intending for two decoupling caps to be used...one cap from V+ to ground, and another from V- to ground. There's no ground reference on the Surfboard, so any dual-capacitor bypass scheme (which is the norm) would have to take place on the 6800's PC board...as close to the original 7136 solder holes as you can get them. The Surfboard has connection pads to add a SMD cap from Pin 4 to Pin 8...their intention being to employ a lesser-used (and generally less effective) method of bypassing by installing a capacitor from V- to V+. One, this doubles the voltage rating needed for the cap. Two, single channel opamps have the positive supply on Pin 7, not Pin 8, which renders the nifty pad that the Surfboard has pretty useless. While local bypassing is generally a good thing, neither the OPA604 or the LME49870 are finicky devices and probably will do fine if you do the bypassing on the Pioneer PC board (and would likely work just peachy with no bypassing at all).

#3. We don't really care what the offset is of the 7136...they're coming out, right? Once the new opamps are in place and working, connect your ground lead on your meter to a decent ground (chassis is fine) and with no signal, look at Pin 6 of the Surfboard with the meter set to read DC millivolts. We're looking to see how much DC is on the output of the opamp...if it's low enough, the coupling caps (listed in my previous post) are superfluous. This is one of the major advantages of moving to a modern opamp...DC precision may well allow you eliminate those caps, and getting rid of those caps is a potential positive change every bit as important as the whole opamp swap.
 
I will post this here, and not in my scratch pad above.





I have visually checked the listing of the parts from page 21 in the manual , to the schematic. I think I have all of them.

I am now scrubbing other cap lists for the crossref PN's.

Only Electrolytic; and a few noise filter caps I might replace for fun.

SA-6800 Re-cap list
(Pending review)

Phono EQ assembly (GWF-122)

GWF-122: C101-102: CEANL 2R2M 50 2.2uF 50v CEANL: 647-UKL1H2R2MDDANA 2.2uF 50v
GWF-122: C107-108: 220 6 CEA 221P 6 647-UPW0J221MED
GWF-122: C109-110: CEANLNP 2R2M 50 2.2 50 (Non Polarized) Do we do NP;or low leakage?
GWF-122: C117: CEA 101P 25 100 25 647-UPW1E101MED
GWF-122: C118: CEA 470P 25 470P 25 647-UKL1E470KEDANATD


AF Assembly (GWF-127)

GWF-127: C101-102: CEANL 2R2M 50 2.2uF 50v CEANL: 647-UKL1H2R2MDDANA 2.2uF 50v
GWF-127: C207-208: ACH-318
GWF-127: C211-212,245: CEANL 010M 50 647-UKL1H010KDDANA
GWF-127: C223-224 CEANL 4R7M 25 647-UKL1E4R7KDDANA
GWF-127: C229,230 :CEANL 010M 50 647-UKL1H010KDDANA
GWF-127: C237,C238,249 CEA 470P 25 47 25 647-UPW1E470MDD
GWF-127: C239: CEA 471P 25 647-UPB1H471MHD
GWF-127: C240: CEA 101P 25 100 25 CEA 101P 25 647-UPW1E101MED
GWF-127: C241,242: ACH-082
GWF-127: C244: CEA 101P 50 647-UHE1E101MED
GWF-127: C246: CEA 471P 6 647-UKL1A471KPD (10VDC)
GWF-127: C247: AGC-004

Indicator Assembly (AWH-041)
AWH-041: C1,2: CEANL 0R1M 50 647-UKL1H010KDDANA
AWH-041: C3: CEA 101P 16 647-UVZ1C101MDD
AWH-041: C4: CEA R47P 50 UVZ1H4R7MDD1TD

Volume Assembly
(None
 
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I'm not going to doublecheck that list, but know that any electrolytic up to and including 2.2µf 50V can and should be replaced with a stacked film cap. Mouser carries the Panasonic ECQV(L)(M) series caps, and they work great.

There's no need to fool with anything other than the electrolytic caps (I see other types on the list...recommend leaving them alone).
 
IF you plan on going to all this trouble, you need to plan on using the best caps available. That means 105°C low-impedance jobs. If you want to use Nichicon, then use the Nichicon UPW or UHE. Your job to look up part numbers...I want to help, but that's a bit too time consuming for me.

I mentioned in Post #3 that C109, C110, C207, and C208 might be replaced with a jumper wire, but until you have a chance to measure the offset on any replacement opamps, pop in a new capacitor. All of these are non-polar caps, which is something totally different from a low-leakage cap. In any case, I'd be using the Panasonic 2.2µf 50V stacked film caps (part #667-ECQ-V1H225JL) for C109 and C110, and the WIMA 4.7µf 50V or Kemet 4.7µf 50V film caps (part numbers 505-MKS2-4.7/50/10 and 80-MMK5475K50J06TR18). Any time there's an option to replace a non-polar electrolytic (which are generally sucky) with a film cap of any type (all film caps are non-polar, and the worst film cap is better than any electrolytic), you should try to do so. These caps are good enough that you can ponder replacing them with a jumper wire at your leisure...or not bother replacing them with a jumper at all and just leave the film caps in place.

I don't see C209 and C210 in there. 10µf 25V. Or C213/C214. And if you can fit another of the WIMA or Kemet 4.7µf 50V caps in place for C223 and C224 you'll improve the sound of the power amp appreciably.

I don't see anything to gain by replacing C247. It's just a bypass on the rectifier diodes on the secondary side of the transformer. No reason to mess with it.
 
EchoWars said:
IF you plan on going to all this trouble, you need to plan on using the best caps available. That means 105°C low-impedance jobs. If you want to use Nichicon, then use the Nichicon UPW or UHE. Your job to look up part numbers...I want to help, but that's a bit too time consuming for me.
Click to expand...

Yes;you are correct. Your advice and that of MarkTheFixer is always appreciated.

EchoWars said:
I mentioned in Post #3 that C109, C110, C207, and C208 might be replaced with a jumper wire, but until you have a chance to measure the offset on any replacement opamps, pop in a new capacitor. All of these are non-polar caps, which is something totally different from a low-leakage cap. In any case, I'd be using the Panasonic 2.2µf 50V stacked film caps (part #667-ECQ-V1H225JL) for C109 and C110, and the WIMA 4.7µf 50V or Kemet 4.7µf 50V film caps (part numbers 505-MKS2-4.7/50/10 and 80-MMK5475K50J06TR18). Any time there's an option to replace a non-polar electrolytic (which are generally sucky) with a film cap of any type (all film caps are non-polar, and the worst film cap is better than any electrolytic), you should try to do so.
Click to expand...

Yes; I will replace the output caps.

EchoWars said:
These caps are good enough that you can ponder replacing them with a jumper wire at your leisure...or not bother replacing them with a jumper at all and just leave the film caps in place.
Click to expand...

I will put a DVOM and see if I can add a jumper in the coupling caps place.

EchoWars said:
I don't see C209 and C210 in there. 10µf 25V. Or C213/C214. And if you can fit another of the WIMA or Kemet 4.7µf 50V caps in place for C223 and C224 you'll improve the sound of the power amp appreciably.
Click to expand...

Yes, I actually missed quite a few.. including the power supply main caps.

EchoWars said:
I don't see anything to gain by replacing C247. It's just a bypass on the rectifier diodes on the secondary side of the transformer. No reason to mess with it.
Click to expand...

Will do.


OK; here is the revised list. I left ample documentation; and I have multiple parts for the power supply main caps.

8000uf not available; so I selected a few alternates.



__________________

Panasonic
667-ECE-T1JA123EA
Capacitance: 12000uf

Panasonic
667-ECO-S1HA103DA
11000uf

Nichicon
647-LGU1H103MELB
Capacitance: 10000 uF

These have been verified to fit, but are not drop in.There is ample room to re-drill the PWBA to make fit.
____________________________________________________________


SA-6800 Re-cap list
(Pending review)

Phono EQ assembly (GWF-122)

GWF-122: C101-102: CEANL 2R2M 50 2.2uF 50v Panasonic 2.2µf 50V stacked film caps 667-ECQ-V1H225JL OR KEMET Film Capacitors 2.2uF 50VDC 5% 80-R82CC4220Z370J

GWF-122: C107-108: 220 6 CEA 221P 10 Volt 220uF Nichicon Aluminum Electrolytic Capacitors - Leaded 10 Volt 220uF 105C 8x11.5 3.5LS 647-UKL1A221KPDANA Or Nichicon Aluminum Electrolytic Capacitors - Leaded 16 Volt 220uF 105C 10x12.5 5LS 647-UKL1C221KPDANA

GWF-122: C109-110: CEANLNP 2R2M 50 2.2 50 Panasonic 2.2µf 50V stacked film caps 667-ECQ-V1H225JL OR OR KEMET Film Capacitors 2.2uF 50VDC 5% 80-R82CC4220Z370J

GWF-122: C117: CEA 101P 25 100uf Nichicon Aluminum Electrolytic Capacitors - Leaded 100uF 25 Volt 105C 8x11.5 10% 647-UKL1E101KPDANA Or Panasonic Aluminum Electrolytic Capacitors - Leaded 100uF 667-EEU-FC1E101S

GWF-122: C118: CEA 470P CEA 470P 25 470P 25 Panasonic Aluminum Electrolytic Capacitors - Leaded 47uF 25V- 55 C to + 105 C 667-EEU-FC1E470 or 667-ECA-1EHG470 OR Nichicon Aluminum Electrolytic Capacitors - Leaded 25volts 47uF 105c 5x9 2LS 647-URZ1E470MDD


AF Assembly (GWF-127)

GWF-127: C101-102: CEANL 2R2M 50 2.2uF or Panasonic Film Capacitors 2.2uF 50V 5% 667-ECQ-V1H225JL OR KEMET Film Capacitors 2.2uF 50VDC 5% 80-R82CC4220Z370J


GWF-127: C207-208: ACH-318

GWG-127: 209-210-213-214: CEA 100P 25 10uf Nicicon Low Leakage Electrolytic Capacitors Aluminum Electrolytic Capacitors - Leaded 25 Volt 10uF 5x11 10% 647-UKL1E100KDDANA or Panasonic Aluminum Organic Polymer Capacitors 25volts 10uF ESR 60mohm 667-25SEP10M

GWF-127: C211-212,245: CEANL 010M 50 Panasonic Film Capacitors 1uF 50V 5% 667-ECQ-V1H105JL Or Kemet Film Capacitors 50volts 1uF 5% LS 5mm 80-MMK5105J50J02TA18


GWF-127: C223-224 CEANL 4R7M 25volt (No 25v available) 4.7 50 10 Wima 505-MKS24.7/63/5 Lead Spacing = 5 mm Film Capacitors 63V 4.7uF 5% or Kemet Film Capacitors 50volts 4.7uF 10% LS 5mm 80-MMK5475K50J06TR18

GWF-127: C229,230 :CEANL 010M 50 Kemet Film Capacitors 50volts 1uF 5% LS 5mm 80-MMK5105J50J02TA18 or Panasonic Film Capacitors 1uF 50V 5% Polyester ECQ-V1H105JL

GWF-127: C118,C237,C238,249 CEA 470P CEA 470P 25 470P 25 Panasonic Aluminum Electrolytic Capacitors - Leaded 47uF 25V- 55 C to + 105 C 667-EEU-FC1E470 alternate Aluminum Electrolytic Capacitors - Leaded 47uF 25V Tolerance: 20 %
Voltage Rating: 25 V Operating Temperature Range: - 55 C to + 105 C Case Diameter: 5 mm Lead Spacing: 2 mm High Temp 667-ECA-1EHG470 or 667-ECA-1EHG470 OR Nichicon Aluminum Electrolytic Capacitors - Leaded 25volts 47uF 105c 5x9 2LS 647-URZ1E470MDD

GWF-127: C239: CEA 471P 25 647-UPB1H471MHD

GWF-127: C240: CEA 101P 25 100 25 :Nichicon Aluminum Electrolytic Capacitors - Leaded 50volts 100uF 150c 10x12.5 5L 647-UBX1H101MPL
_________________________________________________________
PSU GWF-127: C241,242: 8000 50v Add 1uf 50 v across main caps)

(667-ECE-T1JA123EA :Capacitance: 12000uf
Tolerance: 20 %
Voltage Rating: 63 V
ESR: 0.028 Ohms
Operating Temperature Range: - 40 C to + 105 C
Series: T-HA
Diameter: 35 mm
Length: 50 mm
Lead Spacing: 22.5 mm
Product: General Purpose Electrolytic Capacitors
Capacitance - uF: 12000 uF

667-ECO-S1HA103DA 11000uf
Panasonic
Manufacturer: Panasonic
Product Category: Aluminum Electrolytic Capacitors - Snap In
RoHS: RoHS Compliant Details
Capacitance: 0.01 Farad
Tolerance: 20 %
Voltage Rating: 50 V
ESR: 0.033 Ohms
Operating Temperature Range: - 40 C to + 105 C
Series: TSHA
Diameter: 30 mm
Length: 50 mm
Lead Spacing: 10 mm
Product: General Purpose Electrolytic Capacitors
Capacitance - uF: 10000 uF
Dissipation Factor DF: 25
Load Life: 3000 hr

647-LGU1H103MELB
Nichicon
Capacitance: 0.01 Farad
Tolerance: 20 %
Voltage Rating: 50 V
Operating Temperature Range: - 40 C to + 105 C
Series: GU
Diameter: 30 mm
Length: 50 mm
Lead Spacing: 10 mm
Product: Aluminum Electrolytic Capacitors
Capacitance - uF: 10000 uF
Leakage Current: 2.12 mA
Ripple Current: 4090 mA

***************__________________________________________

GWF-127: C244: CEA 101P 50 100uf 35:Nichicon Aluminum Electrolytic Capacitors -Aluminum Electrolytic Capacitors - Leaded 35volts 100uF 150c 10x20 5LS 647-UBX1V101MPL

GWF-127: C246: CEA 471P 6 470uf (16v) Nichicon Aluminum Electrolytic Capacitors - Leaded 16volts 470uF 150c 12.5x20 5LS 647-UBX1C471MHL

GWF-127: C247: AGC-004

Indicator Assembly (AWH-041)

AWH-041: C1,2: CEANL 0R1M 50 .1UF 50v Kemet Film Capacitors 50volts 0.1uF 5% 80-MMK5104J50J01TR18

AWH-041: C3: CEA 101P 16 Nichicon Aluminum Electrolytic Capacitors - Leaded 16volts 100uF Snap-In 647-URZ1C101MDD

AWH-041: C4: CEA R47P 50 Panasonic Aluminum Electrolytic Capacitors - Leaded .47uF 50V 667-ECA-1HHGR47

Volume Assembly
(None)
 
The 8000µf 50V cap can be tricky...it is soldered directly to the PC board, so physical size and pin spacing matter. Chances are that the stock caps are a three-terminal job...one positive, one negative, and a third isolated pin for mechanical support. You don't need the third pin, but finding something to fit the other PC board holes may be a challenge (two terminal snap-in caps have a pin spacing of 10mm, for instance). You're the man on the spot, so the decision as to what to buy, and how to mount it is going to have to be your own. You may have to get creative to get it done, but keep in mind...neatness counts.
 
Hi Echowars,

Okay, actually did not investigate before I spoke.:nono:
makes sense, add a 2 to 604, :D
I have considered offering upgrade kits to selected Pioneer gear.
Like in this case, offer a new phono design for an old cow. Add MC support if needed etc.
Need to know the physical dimensions of the pcb's, Pioneer does not document this stuff. Lots of ideas, but don't think that there is enough market.
So just offer advise instead.
Rick
 
EchoWars said:
Well, there's the flashing 'NEW!' gif next to the pic, so they obviously decided to make one just recently.]
Click to expand...

Hmmm, I missed that as I never went to their Homepage.

I've ordered a couple for the SX-780 I have with the dead TA7136 chip. Will report back after the repair although it wont be until after Christmas.
 
Let us know what you end up with and how it compares. I might do that to my 790.

Larry
 
Will these be for simple replacement of a failed TA7136 chip, or do they actually improve the units they fit in?

Speaking of that, what other Pioneers use the TA7136 chip?

If they are an improvement, can one of you Brainiacs (:D) make a post on how to do it for the SX-780 or other units? :yes:

elvi,
I've added this post as a recap list for the SA-6800 in my Pioneer Recap list thread! :thmbsp:
 
Marty said:
Will these be for simple replacement of a failed TA7136 chip, or do they actually improve the units they fit in?

Speaking of that, what other Pioneers use the TA7136 chip?

If they are an improvement, can one of you Brainiacs (:D) make a post on how to do it for the SX-780 or other units? :yes:

elvi,
I've added this post as a recap list for the SA-6800 in my Pioneer Recap list thread! :thmbsp:
Click to expand...

according to my current records:
ONLY THE:
SX-550(2; phono), SX-650(2; tone), SX-750(4; phono & tone),
SX-780(2; tone), SX-880(2; tone)
use it

NOT the SX-450, SX-850, SX-950, SX-1050, SX-1250
NOT the SX-580, SX-680, SX-980, SX-1080, SX-1280, SX-1980
NOT the SX-3400, SX-3500, SX-3600, SX-3700, SX-3800, SX-3900
NOT the SX-D5000, SX-D7000
(exclusions are important too.)
and as far as I can tell, not the x2x and x3x series either - so this is pretty comprehensive.

edit - see EchoWars post about the power supply voltages being too high for most chips, and my "fixes" below.
 
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