QRX Restore....anyone used them before?

Hey there,

Justin here, Jim's son, owner operator at QRXrestore, and the one that has done most of the recapping/soldering since we started some 7 years ago. Just gonna pop in on the dolby bypass. I take the signal at the inputs to dolby circuitry, run it through the tape selector switches, then to the resistors on the dolby push button board that are the outputs of the board. R01 and R02 if I remember correctly. Tape playback is fully functional. This bypass was inspired by accidentally breaking one of those ribbon connectors that connect the two dolby boards on my own 9090. But you know, I wasn't listening to too much dolby fm anyways...


If you want to know how to adjust the diff mod I can tell you. On the F - 2624 put your MM on the 2 22ohm resistors I have put in place of the jumpers that were in R13-R16. Those are there just so that you can measure the difference between these points. I should have placed them in there so you can only get to the correct side of the resistor, while the other side of the resistors are connected together. Measure mV across these points. Adjust the multiturn trim pot I added in R11 and R12 so that your meter reads 0. This will affect offset, and the number doesn't settle till the amp has warmed up. For this reason I usually have one meter on offset, and one on those resistors. Leave the amp running for 3-5 minutes, then set both of these for 0. Once you have set one side for 0 you can move onto the other side and do the same thing. I always set bias after doing these adjustments as the offset can affect the bias to a small degree. Note: Odd numbers will be for the left channel, and even for the right.


Thanks for everyone's support

Justin @ QRXrestore
 
Was going to, but their prices (a grand to restore any QRX model + $115 for LED's ?) were/are astronomical, plus my cost of shipping a 50lb box back and forth to Eugene, OR., ultimately closed the deal for me.
Being able to do some work myself, i studied up on the 9001. The idea of getting that board out, and restringing the dial tuner killed it for me. The string is a longnone... then, lets say i do pin the board, cap it and forget xaps on the tuner because im not going to align it im still left with a bunch of other stuff i have no clue about. Noisy transistors and whatever else.
Im then out countless hours for a job thats not near as good as QRX or the other quad guys can do. If you, can find a professional QUADRAPHONIC tech that can do one of these cheaper, then why not enlighten me?
Having had 4 units done (drove them down to Eugene) 2 of them 9001, this receiver is well worth the money.
Yes, there have been little "this and thats" left over here and there as noted by others.
Also, ive had work done (shipped them out) by Ready Audio, Tom Williams, (for 6 Marantz) Tandberg, (packrat) Scott (vintage tube audio) Fisher and so on. Ive paid premium bucks for ALL OF IT. and, all of it had "a little something" maybe here and there.
This, is the life of vintage audio. For you 1963chris, the price on the 9001 to ME is worth it, given whats involved. If you think "getting it done" for less money is the way to go, then clearly you must have firm grasp on what it takes to complete one (correctly) yes. And for others with, like myself, little "this and thats " left over, then i agree with the premise that once the bulk of the work i dont want and really am not qualified to do is done, i can detail it further. Anything else, i bring up with the builder.
What i do not "expect" is a perfect result every single time. I am eternally greatful for the work of these individuals. Mainly because ALL OF THEM supply so much free information and contribute to "the cause" as for me personally to overlook a minor discrepencey if there is one here and there.
Anyone (like myself) who has had ANY issue after a build, i suggest we take it up directly with the builder. Ive found that all have been willing to get me straightened out. STUFF HAPPENS.
$ 1250 is a premium price for premium service. "Astronomical" it is NOT.
what is Astronomical is the performance of the 9001 for a receiver. There are only 2 people in the country i would send my quad to. Yes, maybe others can "get it done", but 2 that "specialize" in QUAD that i am aware of. Glad one is within driving distance!
Thank you Justin for the diff mod adjustment procedures. 20180915_234025.jpg
 
Last edited:
Hey there,

Justin here, Jim's son, owner operator at QRXrestore, and the one that has done most of the recapping/soldering since we started some 7 years ago. Just gonna pop in on the dolby bypass. I take the signal at the inputs to dolby circuitry, run it through the tape selector switches, then to the resistors on the dolby push button board that are the outputs of the board. R01 and R02 if I remember correctly. Tape playback is fully functional. This bypass was inspired by accidentally breaking one of those ribbon connectors that connect the two dolby boards on my own 9090. But you know, I wasn't listening to too much dolby fm anyways...


If you want to know how to adjust the diff mod I can tell you. On the F - 2624 put your MM on the 2 22ohm resistors I have put in place of the jumpers that were in R13-R16. Those are there just so that you can measure the difference between these points. I should have placed them in there so you can only get to the correct side of the resistor, while the other side of the resistors are connected together. Measure mV across these points. Adjust the multiturn trim pot I added in R11 and R12 so that your meter reads 0. This will affect offset, and the number doesn't settle till the amp has warmed up. For this reason I usually have one meter on offset, and one on those resistors. Leave the amp running for 3-5 minutes, then set both of these for 0. Once you have set one side for 0 you can move onto the other side and do the same thing. I always set bias after doing these adjustments as the offset can affect the bias to a small degree. Note: Odd numbers will be for the left channel, and even for the right.


Thanks for everyone's support

Justin @ QRXrestore
Hey Justin, will the diff adjustments be similar for the 990/9090? Herse is mine with the Padauk wood case you folks rebuilt for me- Nice to see you here on AK.20171222_092954.jpg
 
Come on Justin , you managed to get me interested in your exceptional work anyway.
I was thinking of shipping my 9001 from Greece for a rebuild, but the cost is devastating. Something like a 1000e with a bit of insurance.
I'll have to think it twice , before I do something like this. I work in Budapest , and spend my 9 days off that are not 9 , more like 6 or 7 in Athens.
Very sad for Jim's loss. Never met him , but I know he was a special person.
Regards.
 
Last edited:
I seem to get very sentimental as far as people are concerned In this topic.
We all age as we go. I can't deal with loses.
I need to have my buddies around me. I like people. Even when I argue with them. I like people and they sure are missed , when they are away. Only away , not passed . I can't deal with that.
I know I have you tired all you up .
Sorry.
 
Sorry to hear about Jim, he was very helpful when I restored my 9001, offered welcome tips and advise. He will be sorely missed.
 
Hey Justin, will the diff adjustments be similar for the 990/9090? Herse is mine with the Padauk wood case you folks rebuilt for me- Nice to see you here on AK.View attachment 1356801


Hey! I remember that unit! The case looks great. So the adjustment is very similar but not exactly the same because the driver board is different. It is the same for the 990Db/9090db however. For the 9090 the 22ohm resistors will have been in the place of stock 22ohm resistors on R13-R16. Same thing I should have put them in so you can only get to the correct side. I only put in new ones so you can get your probe on there. Put your MM there, adjust the multiturn pot in R11 and R12 right next to the resistor pairs. Adjust for 0. Other than the locations of the components the adjustment is done exactly as I described above.

Thanks again for everyone's support!

Justin
 
I’m a happy customer, I had my 9090 restored by QRX with the differential mod a few years ago, it gets lots of use and sounds great. A friend dropped it off for me, and QRX restore built a real sturdy box for shipping it back to me. Definitely will use them again.
I echo people’s sentiments about Jim. A great guy, very personable and fair.
 
I have bought two units from Qrxrestore. An Eight Deluxe and a 9001. The latter was the first one that I bought from Jim.

I’m not technically skilled and that’s why I don’t write here very often but I enjoy reading comments and tips on vintage Sansui gear.

Jim was always nice and patient towards me specially dealing with someone with a lot of “electronic limitation”. He never ceased to reply to my emails… Back then, 3 years ago, I was leaving in Africa (I work in the oil industry so my wife and I have lived in very interesting places so far) and the heavy and big 9001 was beautifully and professionally shipped in a strong cardboard box. It arrived without a scratch! I remember Jim asking to let him know as soon as the unit arrived at final destination… I did so and he was glad to know that everything was in order.

Later, Jim told me about the Eight Deluxe. The same thing, from Oregon to Angola! I didn’t hesitate. This one has a new wood cabinet and in terms of sound, I prefer the Eight over the 9001. But one is apple and the other is orange, a comparison is not fair however as I listen only in stereo mode I still prefer the 8 Deluxe. Everything went really smooth. No worries at all.

The 9001 is dropping a channel now, I think it has to do with the speaker selector or the Dolby selector. This is a complex unit with lots of electronic parts and mechanic selectors. Just like us, in the eternal aging process, something may go wrong even after a recent checkup at the doctor… It’s nobody’s fault. Now I’m looking for a skilled technician in the The Hague area (Netherlands) to help me with this beautiful receiver. I wish I have a Qrxrestore close to me…

It’s terrible to hear that Jim has passed away and I express my sincere sympathy to the family.

Qrxrestore, carry on with the fantastic job you guys do!

Fabio
 
Last edited:
I'm impressed that they sell the improved fusible resistors, and, some caps & transistors, for the DIY to do there own fixes. Some repair places would keep such weak points a trade secret.
 
Has the 4 channel selector board, F2632, been pinned?


http://www.qrxrestore.com/restoring-the-9001/

This is one of the reasons I'm leaning towards buy a 6001/7001, instead of the 8001/9001. Pass through vias on circuit boards have been an issue with other electronics, as well.
He bought the 9001 direct fron QRX Restore. Its been pinned. Likely a tape switch or relay ect.
 
I have bought two units from Qrxrestore. An Eight Deluxe and a 9001. The latter was the first one that I bought from Jim.

I’m not technically skilled and that’s why I don’t write here very often but I enjoy reading comments and tips on vintage Sansui gear.

Jim was always nice and patient towards me specially dealing with someone with a lot of “electronic limitation”. He never ceased to reply to my emails… Back then, 3 years ago, I was leaving in Africa (I work in the oil industry so my wife and I have lived in very interesting places so far) and the heavy and big 9001 was beautifully and professionally shipped in a strong cardboard box. It arrived without a scratch! I remember Jim asking to let him know as soon as the unit arrived at final destination… I did so and he was glad to know that everything was in order.

Later, Jim told me about the Eight Deluxe. The same thing, from Oregon to Angola! I didn’t hesitate. This one has a new wood cabinet and in terms of sound, I prefer the Eight over the 9001. But one is apple and the other is orange, a comparison is not fair however as I listen only in stereo mode I still prefer the 8 Deluxe. Everything went really smooth. No worries at all.

The 9001 is dropping a channel now, I think it has to do with the speaker selector or the Dolby selector. This is a complex unit with lots of electronic parts and mechanic selectors. Just like us, in the eternal aging process, something may go wrong even after a recent checkup at the doctor… It’s nobody’s fault. Now I’m looking for a skilled technician in the The Hague area (Netherlands) to help me with this beautiful receiver. I wish I have a Qrxrestore close to me…

It’s terrible to hear that Jim has passed away and I express my sincere sympathy to the family.

Qrxrestore, carry on with the fantastic job you guys do!

Fabio
1. What points to speaker or dolby selector?
2. How often, and at what volume level does it cut out? Meaning, are you generally listening at low volume when it does it, and does it cut out every time its used?
3.same channel every time?
 
He bought the 9001 direct fron QRX Restore. Its been pinned. Likely a tape switch or relay ect.

Correct. The Dolby board has been pinned by qrx restore. And I know it's prone to problems...

1. What points to speaker or dolby selector?


2. How often, and at what volume level does it cut out? Meaning, are you generally listening at low volume when it does it, and does it cut out every time its used?

3.same channel every time?

1 - Speaker selector mainly. When listening to FM, I move the Dolby nr selector from off to FM Dolby position and problem disappears. In other words, faulty channel comes back.
Channel drops only in stereo mode using either FM or AUX.

2 - I'm generally listening at low volume and it always happens. If I turn the volume up, like 13 hours or more, the faulty channel comes back but in an intermittent way.

3 - Correct. Always the same.
 
Last edited:
Having had 10 or so 990, 9090db and six 9001/999 i have heard tell about dolby problems but only experienced it once.
IF qrx pinned the QUAD board, then i would look elsewhere. One problem i had with mine even after rebuild was speaker realy. Low level listening, just not enough power to get through the corrosion. How i determined this to be the falt was with headphones. The 9001 has no relay switch, in that the speaker selector has no "off" position. I ran mine at low volume until the problem came up, then used headphone jack. Headphones do activate the relay and kick out the speakers. In and out a few times, if the channel changed or came back then it told me relay. I replaced that relay, and have had no trouble since. The adapter you see in the pic converts standard headpjone down to the 3.5mm. I use this to deactivate my speakers before i turn off my 9001. I dont like my speaker on with power on. Not releveant in a way, but this is what i use to trip my relay. Grab some headphones, make it makfunction and see if cycling the relay brings back the channel. While your there, have a listen and see if its akso intermittent through headphones. 20190212_154400.jpg

2 - I'm generally listening at low volume and it always happens. If I turn the volume up, like 13 hours or more, the faulty channel comes back but in an intermittent way.
 
I just leave the adapter in the hole and push it all the way in before i shut it down. Why? Well, i like to:
1. Turn volume all the way down
2. Shut off speakers
3. Before i shut them ("them"being all amps and receivers that i own and jave owned) down.
This way, my speakers are not engaged when it powers up just in case of failure, and with volume down the switch doesnt take a current in rush. Is this true? Not sure, but its the way i was taught. Also, i run in aux mode 90%of the time. I dont leave fm engaged. I turn that selector to phono and kill the fm. Not sure if it helps save anything, just cant see keeping it powered when i dont use it. Its just maybe something unimportant, and im ok with it. Ive however only heard a speaker THUMP once in my 50 years.20190212_155147.jpg
 
Last edited:
Hi Justin, I'm so sorry to hear about your dad although I know it's old news by now.

I've been using a QRX-7001 in the bedroom for a while now and it's developed several issues that I think I can fix but would like an informed opinion on. Would you mind if I PM'd you about it?

It is too bad you don't work on Marantz; I had high hopes for a 4270 but I'm picking it up from the second tech who's given up on it tomorrow!
 
Back
Top Bottom