• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

TX-8100 worth restoration?

KeithD

KeithD

AK Subscriber
Subscriber
I have a TX-8100 to go along with my SA-8100. I picked up this tuner off of e-bay last summer for about $70 + shipping. Come to discover that it had one or two lights not working and it needs an alignment - scale is off and it's not linear, so I can't just move the indicator pointer. I got a partial refund because of the issues. I've now believe it is also putting out static somewhat randomly to the amp. Looking at the service manual, I see a number of transistors that are known to be problematic.

So, here's my question, I can buy the parts to recap all the electrolytics and replace all of the problematic transistors, but after all that work it will still need an alignment. I'd have to send it out for the alignment, since I don't have the equipment needed to do it myself, and there is no one near me that does to my knowledge. Is this tuner worth all that work, or should I be looking for something else? I like that it matches the 8100 and the cosmetics are good, but otherwise, I have not found this to be a "great" tuner that pulls in a lot of stations flawlessly. Just not sure it is worth sticking a bunch of money into it as compared to finding a fully working one.
 
Register to hide this ad
the parts would not be much money but aligning it could be an issue so why spend $ if you cant get it to work properly. you could have the same problem with a so called working one.
you can check to zero the discriminator as shown in the procedure step 9, adjust for 0VDC across the tuning meter using a plastic tuning tool.
 
Yes, you hit upon my problem. I don't have any tools to align or adjust a tuner, not even a plastic or ceramic tuning tool. Just like this one, I think a lot of tuners are listed as working when really they need a full service. I can only assume people are willing to live with the problems when they pay the kind of money these get on e-bay. I wanted a the matching tuner for my SA-8100, but it's not turned out as well as I hoped.

Right now I have pulled this tuner out of my system. I'm using an Onkyo Integra T-4015 tuner instead that I picked up at Goodwill a while back for $7. Working much better than the TX-8100. I happen to have the silver version, so it does not look out of place in my setup.
 
do not throw out the tx-8100, it has lots of good parts in it.
i'd give it ago fixing it but shipping costs are a killer.
onkyo had good equipment.
 
Not going to throw it out, just don't feel comfortable using it at this point with the problems. A few days ago it was putting a lot of static out to the amp. That's when I took a look at the service manual and saw lots of transistors on the "worst transistors" list. Right now it is on my "needs work" stack. It may stay there until I have time to spend on it, but it will still be a big leap to send it out for alignment. I believe that service is about $80 + shipping. These tuners in "working" condition seem to sell between $100-150, so with the $60 I already have in it, it will be a loss to truly "restore" it. I may end up selling it "as is" and let someone else deal with it.

I agree, the Onkyo is nice, so for now, I will enjoy that! I do like the looks of the manual dial tuners, but the digital quartz lock tuners are really convenient.
 
all common small signal bjts as used in other units, ksa992,ksc1845 and Nichicon UKL ecaps for signals, UPW for power supply sections.
not to much work to get a BOM together
switching bjts are ksa733c,ksc945c
$20-30 worth of parts
 
Yes, yes, I agree, BOM and buying parts are not the problem. It's time invested to do the restore and then $$ to send out for alignment. I may decide to do all of the above, but I realize this will not be $$ invested for future profit.

I think my MAIN question was whether, in the grand scheme of pioneer tuners, the 8100 is on the high end and worth the effort/$$?

As a reference, I could pick up a TX-8500II from a guy whose got one locally for $95, or possibly less. Is that $$ better spent?
 
I have not cleaned the switches. I have not noticed any issues when changing the switches. To me, this did not sound like a dirty switch issue. This was more likely transistor(s) causing pops and static bursts. As I mentioned, there are a number of suspect transistors in this unit that most recommend replacing including 2SA725 in the amplifier unit.
 
KeithD said:
...As a reference, I could pick up a TX-8500II from a guy whose got one locally for $95, or possibly less. Is that $$ better spent?
Click to expand...

The TX-8500II is a fine tuner but aesthetically it's not a match to the earlier 8100 series with that lovely blue backlit dial. Noisy transistors in the output amp are the likely cause of the noise which is no biggie however tuner front end / alignment issues are another matter as you pointed out.

PM sent, I might be able to help...
 
I'd prefer not to go the route of a TX 8500/9500. I'm not thrilled with how they look. It would be mostly based on performance, opinions seem positive about them as tuners, and it's what's available locally at the moment.

I think for now I will continue using the Onkyo and see how I like that until I can sort out the 8100.
 
Update: replaced all of the transistors recommended by MTF here:

http://www.audiokarma.org/forums/index.php?threads/pioneer-tx-8100-restoration.527321/

Did not do Q2 or D3 on the power supply board as they were too difficult to get to, but replaced the rest. Interestingly, the tuner is sounding better just in regular play. Stations seem to come in a bit better and clearer. I'm hoping this has solved my static issues.

Alignment is not terrible, but could be improved. I've set the dial pointer to a local FM station 96.1. Alignment gets further out the farther the dial is from that point. Checking local stations at the ends of the spectrum, 106.3 comes in at a dial setting of about 106.7 and 88.9 is at about 88.5. So, about 0.4 off on both ends, but in opposite directions. Is there a simple way to adjust this, or does it need the service manual alignment process?
 
So i suspect in the middle of the band around 98Mhz it is pretty close to accurate, I do not think that you can do much better.
 
rcs16 said:
So i suspect in the middle of the band around 98Mhz it is pretty close to accurate, I do not think that you can do much better.
Click to expand...
But would an alignment following the service manual improve on this? I have an SX-828 and the tuner is accurate the entire length of the dial.
 
IT's possible to get the band accurate across the whole band, but it will take a lot of patience as each adjustment on one end also affects the other end. Which is why the manual states repeat the pertinent steps until no more change is noted. These IC based tuners are harder to tune than a tube unit IMO. Plus you need some specialized gear to do so. Best to take or send to someone who knows how to tune one up.
 
Last edited:
larryderouin said:
IT's possible to get the band accurate across the whole band, but it will take a lot of patience as each adjustment on one end also affects the other end. Which is why the manual states repeat the pertinent steps until no more change is noted. These IC based tuners are harder to tune than a tube unit IMO. Plus you need some specialized gear to do so. Best to take or send to someone who knows how to tune one up.
Click to expand...
Agreed on seeking service from someone who can do it. Just wanted to clarify if the accuracy can be improved from its current condition. It's playing really well right now and pulling in stations clearly that were weak and static-y before. So, I think its worth doing the alignment. I did not replace any capacitors as (my understanding is) that might have had a negative effect on the alignment and ability to output stereo?
 
i can not be sure if playing with the adjustments will make it any more accurate, it would have to be tried.
usually ecaps in the tuner will not through off an alignment
 
KeithD said:
Update: replaced all of the transistors recommended by MTF here:

http://www.audiokarma.org/forums/index.php?threads/pioneer-tx-8100-restoration.527321/

Did not do Q2 or D3 on the power supply board as they were too difficult to get to, but replaced the rest. Interestingly, the tuner is sounding better just in regular play. Stations seem to come in a bit better and clearer. I'm hoping this has solved my static issues.

Alignment is not terrible, but could be improved. I've set the dial pointer to a local FM station 96.1. Alignment gets further out the farther the dial is from that point. Checking local stations at the ends of the spectrum, 106.3 comes in at a dial setting of about 106.7 and 88.9 is at about 88.5. So, about 0.4 off on both ends, but in opposite directions. Is there a simple way to adjust this, or does it need the service manual alignment process?
Click to expand...
I don't understand the preoccupation with the accuracy of the tuning dial. I don't tune to a frequency, I tune to a station. If my tuner shows 88.9 for a station at 88.3 as long as I found the station I don't care if the dial isn't totally accurate. This is from someone who spent 2 years in the Army intercepting voice communication on basically the FM freq range. It's an analog dial not digital.
 
rohas said:
I don't understand the preoccupation with the accuracy of the tuning dial. I don't tune to a frequency, I tune to a station. If my tuner shows 88.9 for a station at 88.3 as long as I found the station I don't care if the dial isn't totally accurate. This is from someone who spent 2 years in the Army intercepting voice communication on basically the FM freq range. It's an analog dial not digital.
Click to expand...
OK, resurrecting 5 year old thread here. In that time I have acquired the necessary equipment and have done many alignments. What I have found is that an alignment will improve reception of all stations in quality of sound. The improvement is greater the further the alignment is off. So, true you are tuning in a station on an analog tuner, but the dial is an indication of how well aligned the tuner is to an FM signal. That's my experience, YMMV.
 
You must log in or register to reply here.
Back
Top Bottom