I have input signal which is identical on both inputs of the control amp. When looking at the outputs the right channel goes up with manipulation of the volume control but the left does not change and is much higher to start with but again never moves up or down. This is confirmed with what I'm hearing. So splitting the control amp board down the middle (unless there are shared parts and I don't think there is) I will focus on the components and anything connected driving the left side from the control amp board. I think we are making progress here. Thanks again.
SA 9100 Static on left channel - trying to repair need advice/help
- Thread starter scottm015
- Start date
If you are feeling adventurous, you can swap transistors from side to side and when the problem moves - you've got the culprit.
33&athird
Turn on & Tune in
That's very interesting. Intial thoughts are that the volume control is bypassed, or the ground for it has been somehow dissconnected. I think my reasoning is somewhat coorect, though there could be a totally different issue affecting it. If the signal is initally louder, than it means its not being controlled byt the potentiometer...so there has to be a problem at the pot (again, a guess)...two things can cause that, the pot itself (unlikely), or components (or circuit) around it. Something is causing it to be uneffective...maybe someone else has a better answer, and probably far more correct:scratch2:...
EDIT: Markthefixer beat me too it, with a more reasonable answer...while it would be a little work, it would insantly track down the problem.
I might have mispoke as to "anything driving the control amp board" the driving of the control amp board is functioning as it should since both channels go up and down with the volume control. So with that said if it goes in but does not come out, then there is a problem within the control amp board itself. This is good news because this isolates the problem to a few components on the left channel of the control board. So today, as time allows, I will begin measuring through the circuit to isolate exactly where the problem starts. Another good thing here is that I have a working side which has identical components and should give similar measurements to reference, kind of like a road map I guess. Another really good part to this is that the control amp board would probably be the easiest board out of the whole amp to work on since there are only wires connecting at the top unlike most of the other boards which have top and bottom connections.
This has been quite a process. I am in the Industrial Automation field and rarely troubleshoot to component level but we do basically the same thing, check input against output and once isolated to a board level problem, out goes the board and in with a new one. Most of the new technology is heavily integrated circuits, microrocessors, and surface mount components that you really don't want to get into replacing unless you have some very advanced tools and even then the cost is prohibitive due to site labor rates ($300 / hr), and on top of that there are the software drivers misbehaving that always throw a wrench into the whole mix. I have not had this much fun since I was in school. Although this is my first Integrated Amp project I have done a little vintage analog Tuner alignment and repair and find myself fascinated with this stuff so much that I'm thinking of picking up an O'scope and a Freq'Generator. BTW would you have any model number siggestions on these types of tools? I'm thinking older analog scope or software with USB interface something inexpensive.
This has been quite a process. I am in the Industrial Automation field and rarely troubleshoot to component level but we do basically the same thing, check input against output and once isolated to a board level problem, out goes the board and in with a new one. Most of the new technology is heavily integrated circuits, microrocessors, and surface mount components that you really don't want to get into replacing unless you have some very advanced tools and even then the cost is prohibitive due to site labor rates ($300 / hr), and on top of that there are the software drivers misbehaving that always throw a wrench into the whole mix. I have not had this much fun since I was in school. Although this is my first Integrated Amp project I have done a little vintage analog Tuner alignment and repair and find myself fascinated with this stuff so much that I'm thinking of picking up an O'scope and a Freq'Generator. BTW would you have any model number siggestions on these types of tools? I'm thinking older analog scope or software with USB interface something inexpensive.
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33&athird
Turn on & Tune in
That is good news! and comparing it to the other channel is a great way to troubleshoot, since then you have something to go off of. From what i've seen of the internals, it's not too fun to dig stuff out, so if its easy to acess thats good news, I knowon my 727 that the control board is a total pain to get too.
That's very cool stuff, I recently finished a entry-level digital class (just 74lsXX type stuff). The new integrated circuits are both great and terrible, much harder to work on. I finished a nixie tube clock kit that had a surface mount driver chip, soldering that was not fun, but a heck of an experiance. If labor rates are $300/hr maybe I need to go into the field
. Would love to check out the automation stuff at some point...all we have is a radioshack super-armatron, and its mechanical
.[/QUOTE]
There are many topics about o'scopes on the forum, a quick search will pull in alot of suggestions. However, I will say that a analog scope will be cheaper and easier to work with in general. As odd as it souns, analog scopes are better for analog signals, and digital scopes are better with digital signals (imagine!). Haven't tried out a usb device though. There are alot of options out there...the used market is good for these, and something like a convention or gathering for electronic or ham (radio) people may have some good stuff. It's worth noting that a decent multimeter will take you a long way, seems you already have one...besides that, a ocilloscope would be the next step I think:yes:
Labor rates that a company charges is rarely ever close to what the Engineer doing the work gets. 
It is a field full of opportunity though and I'd recommend it to most as long as you don't mind traveling to customer sites all over the world. I wanted to mention since you did the digital class you should look at the Atmel ATmega prototype micro-controllers developer kits. Though I've been out of school for nearly 20 years I recently took an Engineering 3000 level "C" language programming class where we built and programmed robots for autonomous tasks using the ATmega128 product. Talk about fun and challenging. The applications are endless and cheap too.
It is a field full of opportunity though and I'd recommend it to most as long as you don't mind traveling to customer sites all over the world. I wanted to mention since you did the digital class you should look at the Atmel ATmega prototype micro-controllers developer kits. Though I've been out of school for nearly 20 years I recently took an Engineering 3000 level "C" language programming class where we built and programmed robots for autonomous tasks using the ATmega128 product. Talk about fun and challenging. The applications are endless and cheap too.
Places that do surface mount repair have to make a large investment in expensive equipment just to get those little buggers off and on. Not like a cheap desoldering tool, or some braid and an iron.
back to the mundane:
the control amp uses
2sa774 metal can bce 35v 50mA 0.15w 540hfe 65mhz
2sc1478 metal can bce 35v 50mA 0.15w 540hfe 150mhz
2sc1312 to-92 ecb 35v 100mA 0.2w 500hfe 150mhz
and in that stage it's collector current is 5mA , dissipation wattage = 0.08w
Thus
512-KSA992FBU (ln)to-92 ecb 120v .05a .5w 100mhz 150-800hfe $0.05 ea
for the a's, and
512-KSC1845UBU (ln)to-92 ecb 120v .05a .5w 100mhz 150-800hfe $0.05 ea
for the c's will work fine in all positions. They're LOW NOISE to boot, a bonus....
and at a nickle apiece, coupled with the difficulty of accessing the board for diagnosis and repair, I would just pop in all of them.
The boards DO have the symbol marked at the lead locations for identification.
You have missed the entire gist of my earlier advice:
get a line level signal source, tuner, cd or dvd player, and generate a signal, and feed it into the aux input.
Then use a signal probe - simply a 0.1uf ceramic disc cap with one lead connected to the center conductor of an rca interconnect cable, the other cap lead is your probe. The other end of the rca interconnect plugs into an amplifier input - either that unit if the amp's ok ("amp-in") or another amplifier/speaker , another amp's preferred, that allows for volume control, don't forget to establish a ground between the two units - another RCA cable will do fine.
Then you follow the signal in and out until it either disappears, changes or the noise shows up - and having a working channel to reference helps establish relative signal levels.
back to the mundane:
the control amp uses
2sa774 metal can bce 35v 50mA 0.15w 540hfe 65mhz
2sc1478 metal can bce 35v 50mA 0.15w 540hfe 150mhz
2sc1312 to-92 ecb 35v 100mA 0.2w 500hfe 150mhz
and in that stage it's collector current is 5mA , dissipation wattage = 0.08w
Thus
512-KSA992FBU (ln)to-92 ecb 120v .05a .5w 100mhz 150-800hfe $0.05 ea
for the a's, and
512-KSC1845UBU (ln)to-92 ecb 120v .05a .5w 100mhz 150-800hfe $0.05 ea
for the c's will work fine in all positions. They're LOW NOISE to boot, a bonus....
and at a nickle apiece, coupled with the difficulty of accessing the board for diagnosis and repair, I would just pop in all of them.
The boards DO have the symbol marked at the lead locations for identification.
You have missed the entire gist of my earlier advice:
get a line level signal source, tuner, cd or dvd player, and generate a signal, and feed it into the aux input.
Then use a signal probe - simply a 0.1uf ceramic disc cap with one lead connected to the center conductor of an rca interconnect cable, the other cap lead is your probe. The other end of the rca interconnect plugs into an amplifier input - either that unit if the amp's ok ("amp-in") or another amplifier/speaker , another amp's preferred, that allows for volume control, don't forget to establish a ground between the two units - another RCA cable will do fine.
Then you follow the signal in and out until it either disappears, changes or the noise shows up - and having a working channel to reference helps establish relative signal levels.
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Thanks for the instructions. I will try and get to this again today in the evening. I also wanted to post what I found in addition lastnight. I measured the AC and DC on each terminal of the Control Amp assy terminals.
1. 3.2 mVac / .400 Vdc
2. 3.4 mVac / 0.0 Vdc **** This is the output signal for the right channel.
3. 3.2 mVac / .400 Vdc
4. 3.0 mVac / .408 Vdc
5. 3.2 mVac / .400 Vdc
6. 3.2 mVac / 16.67 Vdc *** Power
7. 3.2 mVac / -.096 Vdc
8. 3.3 mVac / -17.04 Vdc *** Power
9. 5.1 mVac / .092 Vdc
10. 3.3 mVac / .097 Vdc
11. 3.3 mVac / .097 Vdc
12. 3.3 mVac / .097 Vdc
13. 3.2 mVac / 0 Vdc *** This is the input signal for the right channel.
14. 0 Vdc Common
15. 16.90 Vdc Power
16. 3.2 mVac / 0Vdc *** This is the input signal for the left channel.
17. ? / -5.59 Vdc
18. ? / -5.60 Vdc
19. ? / -5.56 Vdc
20. ? / -5.55 Vdc
21. ? / -16.83 Vdc *** Power
22. ? / -5.41 Vdc
23. ? / 16.91 Vdc *** Power
24. 5.0 mVac / -5.04 Vdc
25. 10.0 mVac / -5.02 Vdc
26. 4.0 mVac / -4.96 Vdc
27. 7.5 mVac / -1.25 Vdc *** This the output signal for the left channel.
28. 1.0 mVac / -5.05 Vdc
Terminals 16-28 operate the left channel.
At this point I think I blew a speaker from the noisy signal running through them (Vintage small Optimus) and I'm scared that I will blow another so my tests will be with speakers off from here out. I manipulated all controls and these values never changed on the left channel except for the input terminal 16 which varied a little with the volume manipulation but not much. I also saw when I'm touching the casing metal that some of these values would move around, this was also heard when listening to speakers while no real source was fed to the input I have a hum from the phono selections only and it changes loudness as I contact the casing with my hands. I noticed that when first turning on the amp the DC was almost non existent but over time it creeps up to the -5 Vdc point. I'm not sure what this means but with most all control amp board terminals showing -5 Vdc on the left channel is tough to figure out where it is coming from. I noticed these connections go to multiple controls and those controls have multiple caps and other ? components connected to them. Since the input looks ok, it probably is not the volume control being a problem?. I will take the advice from "Markthefixer" that was previously mentioned and continue on tonight as time allows unless you guys see something else, due to these latest results, that I should try.
1. 3.2 mVac / .400 Vdc
2. 3.4 mVac / 0.0 Vdc **** This is the output signal for the right channel.
3. 3.2 mVac / .400 Vdc
4. 3.0 mVac / .408 Vdc
5. 3.2 mVac / .400 Vdc
6. 3.2 mVac / 16.67 Vdc *** Power
7. 3.2 mVac / -.096 Vdc
8. 3.3 mVac / -17.04 Vdc *** Power
9. 5.1 mVac / .092 Vdc
10. 3.3 mVac / .097 Vdc
11. 3.3 mVac / .097 Vdc
12. 3.3 mVac / .097 Vdc
13. 3.2 mVac / 0 Vdc *** This is the input signal for the right channel.
14. 0 Vdc Common
15. 16.90 Vdc Power
16. 3.2 mVac / 0Vdc *** This is the input signal for the left channel.
17. ? / -5.59 Vdc
18. ? / -5.60 Vdc
19. ? / -5.56 Vdc
20. ? / -5.55 Vdc
21. ? / -16.83 Vdc *** Power
22. ? / -5.41 Vdc
23. ? / 16.91 Vdc *** Power
24. 5.0 mVac / -5.04 Vdc
25. 10.0 mVac / -5.02 Vdc
26. 4.0 mVac / -4.96 Vdc
27. 7.5 mVac / -1.25 Vdc *** This the output signal for the left channel.
28. 1.0 mVac / -5.05 Vdc
Terminals 16-28 operate the left channel.
At this point I think I blew a speaker from the noisy signal running through them (Vintage small Optimus) and I'm scared that I will blow another so my tests will be with speakers off from here out. I manipulated all controls and these values never changed on the left channel except for the input terminal 16 which varied a little with the volume manipulation but not much. I also saw when I'm touching the casing metal that some of these values would move around, this was also heard when listening to speakers while no real source was fed to the input I have a hum from the phono selections only and it changes loudness as I contact the casing with my hands. I noticed that when first turning on the amp the DC was almost non existent but over time it creeps up to the -5 Vdc point. I'm not sure what this means but with most all control amp board terminals showing -5 Vdc on the left channel is tough to figure out where it is coming from. I noticed these connections go to multiple controls and those controls have multiple caps and other ? components connected to them. Since the input looks ok, it probably is not the volume control being a problem?. I will take the advice from "Markthefixer" that was previously mentioned and continue on tonight as time allows unless you guys see something else, due to these latest results, that I should try.
Comes a time when the problem is over analyzed and the forest is lost for the trees. It doesn't help that the sa-9100 documentation is the most counter intuitive I have run into out there.... The circuits in the sa-9100 really aren't that radically different than anything else - it's just that who drew it or oversaw the drawing of it was one of the WORST personnel decisions Pioneer EVER made.
The 8100's style is somewhat easier to decipher, and the 8100 resembles the 9100 to some degree.
It's time to order the transistors, and put the 9100 aside until they arrive - so it gets no worse...
I know that may be hard to do, but it must be done.
The 8100's style is somewhat easier to decipher, and the 8100 resembles the 9100 to some degree.
It's time to order the transistors, and put the 9100 aside until they arrive - so it gets no worse...
I know that may be hard to do, but it must be done.
Ordering parts tonight. Kind of nice to have a break. While I'm ordering the transistors, should I get some replacements for all of the electrolytics on the control amp board and should I consider higher grade type caps on this particular board? I was thinking while I have it out replacing parts why not? Maybe this is not necessary but thought I'd ask? I see 18 electrolytic caps listed in the parts list. Also I have some 60/40 solder and I have silver solder. Which would you think is sufficient for the job at hand for best results? I'd like to be sure this baby sings when I'm done and maybe never have to go back into it EVER again. I'm also considering ordering the protection relay and I'm not sure if I can get a perfect replacement but I'm pretty sure it is just a 24DC coil 4PDT. Thank you for the time in helping me sort through this.
On a relay do I want silver, gold over silver, or silver cadmium oxide? Do you know how much the contacts current rating on this should be? I see choices such as 3A or 7.5A and not real sure which to choose. The cadmium is for higher current but not sure if it will conduct as clean as the gold or silver which is around 3A or so. Any suggestions?
33&athird
Turn on & Tune in
I would think any would work. though if your going by conduction, than gold would be best, I belive...that's the reasoning behind gold-plating connectors. The amp rating shouldn't be too high, but i'm not sure how much the amp pulls through, so i'll let Mark handle that...my guess is that the lower of it should work, but am unsure.
Is the relay socketed?, if so, you'd have to match the metals to prevent mis-matched corrosion. However, I don't think pioneer used sockets, so I still think gold would be the best bet. Fun story; in the earlier days of computing you had to match the ram pins to the correct socket metal, or else they would corrode and cease working...I don't think there's been an amp witht hat problem, though.
Gold is a soft metal, not for high contact pressures and multiple actuations OR higher currents. It's perfect for a tape monitor or function switch. Not so much for protection relays.
Best advice is to get it working correctly before starting upgrades.
Being a higher performance amplifier, recapping will not be simple. You will have to list (HOW many times have I said this recently??? but not to you...) all the cap positions, values and special considerations from the parts lists, OR look through my posts for the last few months as I discuss capacitors.
Same with the relays, the answers have been posted in the past on here.
IIAC the 9100's relay is chassis mounted with direct wiring, so adpdt 4pdt 24v relay will work fine, AND with the RIGHT dpdt 4pdt relay should be able to snap the core out of the newer incompatible case and into the older case. I don't have the numbers at hand right now, but I believe I posted just that not too long ago....
Best advice is to get it working correctly before starting upgrades.
Being a higher performance amplifier, recapping will not be simple. You will have to list (HOW many times have I said this recently??? but not to you...
) all the cap positions, values and special considerations from the parts lists, OR look through my posts for the last few months as I discuss capacitors.Same with the relays, the answers have been posted in the past on here.
IIAC the 9100's relay is chassis mounted with direct wiring, so a
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I'm building my list of parts and making notes of location constraints and any dificiencies from my manual parts listing to actual component in place. Since the Transistors and most other components are so reasonable should I just go through and build a selection of Transistors or most components used in the SA 9100 boards? My thought is as I go through these motions I would like to really restore this amp to new condition and should that entail replacing of all caps, transistors, and any suspect or any other component passive or active that could be a problem? I know I'm probably getting ahead of myself here but I'm thinking that with discrete components there is always light at the end of the tunnel no matter how bad the problems and the amp will be fixed eventually so the real question is while you have the boards out to replace maybe just a cap or diode or transistor that is a present problem, shouldn't you just go ahead and replace anything else on that board that could or has ever been a problem through the history of SA 9100 repairs? With that said could you explain how you are cross referencing parts whether it be just by specs or is there a simple cross listing of obsolete part number to new part number out there that I might need in order to accomplish the above process?
My records indicate that the 653-my4-dc24 from Mouser would need some filing, the orange "indicator lever" discarded and trimming of the flash insulator to fit inside that case,
While
This works because the relays are mounted in the chassis rather than mounted on a PCB. (pcb mount use: my4-02-dc24 )
hint: to preserve the wires, cut the terminals off of the old relay, to get the wire and terminal out of the chassis to work on, and cut away most of the visible tab before even attempting to desolder - to minimize heating and preserve the integrity of the wire and insulation. Then desolder briefly exposing more old terminal and then cut that additional terminal away when cold again. The watchword is to preserve the wire. Mark them as they come off, and put them back and solder them one at a time to improve access to the area as you work. Don't restring them all and then try to solder all at once. It just makes life harder.
I DID get 728-fm2110-3005-a standoffs (four?) to form the basis of alternate mounting arrangements.
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Excedrin headache #9100....
explain HOW? An Electrical Engineering education. Treat cross references as a SUGGESTION until you prove they will work in YOUR application....
There's a LONG thread with AK'er SolutionRoom, where he went whole hawg on his 9100 - you may get most of the parts out of it, but also you will also discover that a noise problem was induced by (probably, hasn't been proven yet)TOO much disassembly.
Then there's also MY sa-9100 waiting in line for me to figure out how much is too much or too little.
If you don't find or get the lists of the electrolytic caps and parts from the thread (or him as a LAST resort), get the service manual and transcribe the electrolytic caps and post them like this example drawn from page 48 of 53 in the hires pdf:
aws-039 c1 1uf 25v cssa
aws-039 c5 10uf 16v cea
and so forth for ALL the different boards
then another list of transistors:
aws-039 q1 2sc1313
He did replace many, if not all of the transistors, but his problem stems from ground problems due to the inordinate amount of disassembly he did. He is waiting on me to do my 9100 so we can compare readings to try to fix his problem.
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Parts on order to rebuild the Control Amp assy. Here is a list of parts from mouser that was ordered. The only questionable item was the 1mfd 25v I had to order a 35v because I wanted to go with Nichicon and that was the closest available option, they had no 25v parts available. I'm hoping this will be ok. I'm attaching the list of parts ordered if anyone cares to review. I also picked up the 4pdt relay and a couple of extras but the main focus is to fix my Control Amp board first and if the results are good I will go to the next level. Thanks for the help on this Mark. This might be a long project but hopefully I will be able to have patience through the process and complete it. Also attached a foil side schematic with actual measurements showing the right channel compared to the left channel. All measurements referenced to the chasis ground and only measuring the DC. I will post a new foil side schematic after the change of components that will hopefully correct the problems on this board.
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xoaphexox
Supernatural Anesthetist
Going from 25v to 35v should be fine - I recently rebuilt the control amp assembly in a SA-9100 (replaced every single capacitor and transistor) and the thing sounds fabulous!
I got the parts list vicariously from Mark by using the google search engine. Google searches audiokarma much better than audiokarma searches itself.
To search Google for only one website's results, type something like this:
pioneer sa-9100 site:www.audiokarma.org
That will tell Google to only display results from www.audiokarma.org - VERY useful!
I got the parts list vicariously from Mark by using the google search engine. Google searches audiokarma much better than audiokarma searches itself.
To search Google for only one website's results, type something like this:
pioneer sa-9100 site:www.audiokarma.org
That will tell Google to only display results from www.audiokarma.org - VERY useful!