Onkyo T-9090 II Audio Section Upgrade

jessdw

Active Member
I'm thinking about trying to improve the audio section of my Onkyo T-9090 II. I've read a few things about people replacing some opamps and caps, but I don't have a service manual/schematic. Has anyone done this and remember what you did? I'm sure I could do it if I knew what parts to swap.
 
Okay, so I found a service manual and uploaded it to the AK Database. I won't pretend to be able to read the schematic, but I'm going to give it a try. I think I'll post some pics of the inside of the tuner here as well. Maybe that will spark someone's memory.
 
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Start with Q311 (a dual op amp) and C317 & C318 (22uF/16v nonpolar coupling caps). Those are the last ones before the output. You might try something like an OPA2134 for the op amp, and Nichicon Muse (or Blackgates if you can find them) for the coupling caps.

I'd also definitely use a good quality socket for the op amp, so you can easily switch different ones to see which sounds best to you.
 
Thanks Bob! This is why I love AK. I've got parts on order from AK sponsor Parts Connexion. I looked around a little for Blackgates, but it seems like that ship has sailed. When I opened up the tuner I saw a lot of Nichicon Muse caps, just not the those coupling caps. So that's what I got. I'm really looking forward to this little project!
 
Got this done over the weekend. There is a definite improvement to my ears. Before, I always thought this tuner sounded a little thin, especially in the low end. I'm not great at putting sound into words, but I would say it sounds warmer, less clinical, and has more of a round, full sound. How's that for audiophile speak? A nice upgrade for not a lot of money and working on my own gear gives a nice sense of satisfaction. I'm glad I put the socket in. It will be interesting to try a few other opamps in there. I've got some pictures if anyone is interested.
 
Yeah, I'd like to see pictures. I'm deliberating the upgrade... just not sure I want to alter a pristine piece of equipment. Yet. :D
 
Here is the before picture. The blue caps are the coupling caps. I'll try to take the after pictures soon.

 
Hello Jessdw,
Did you replace more than Q311 opamp(s), and C317/318? I have a never modified T-9090 II that already sounds pretty good, but realize what a few key mods can do to improve on what's already good.

I have a Sony ST-J88B that Terrry DeWick fixed an MPX issue and he also put in 8 pin DIP sockets and replaced the old op-amps with ones I supplied as well as a re-capping in PS and audio sections. This tuner really sounds sweet and I would like to replicate on the T-9090II.

Bill C.
 
I only replaced the Q311 opamp and C317/318. Maybe bobschneider can chime in here. I think I read in an older thread that he had the power supply recapped in his T-9090II. I might be interested in doing that as well, but like I said above, I wouldn't know what to replace unless someone gave me specific instructions.
 
This is the detail for a 2005 Joseph Chow upgrade to a T-9090 II that is now on eb*y. I interpreted this from one of the images in the auction, rather than link to a listing that will be gone in a month.

1) 'Upgrade wiring' to 16 AWG Hi-Q silver plated copper wires for power cord; upgrade to Wattgate plug
2) 'Upgrade wiring' between line filter
3) 'Upgrade wiring' between power transformer and ac switch
4) 'Upgrade wiring' between PCBs and output jacks
5) Upgrade IF ladder PCB at position X151 with 3 150 khz IF filters
6) Upgrade four rectifier diodes to fast speed soft recovery low noise diodes
7) Upgrade C211, C317, and C318 to 47uf/16v Blackgate caps
8) Upgrade power caps to 2200uf/50v Nichicon caps
9) Remove C904, C905, C906, C924, and R901
10) Upgrade Q204, Q301, and Q311 to BurrBrown OPA2134P
11) Upgrade output jacks to Teflon RCAs
12) Align sensitivity, THD, separation, 19khz leakage, and meter calibration

Item number: 190537584412
 
I hope someone can help!

Couple of years ago my Onkyo had been struck by lightning and i need to find the main processor for my 9090II.

As the processor is unique and was only made for this model i can not find a replacement..

Has anyone have a broken 9090II that is wiling to sell?
 
No help whatsoever, there is no main processor spare part anywhere in the world for this tuner and i gave up trying to find one after a couple of years. It is officially a boat anchor.:smoke:

On the bright side i got me a Magnum Dynalab MD 90 to replace my Onkyo.
 
I have a 9090-II lying around...can sell the internals for reasonable cost.
(it has a few missing components, of the most common types, all big IC's & processor & input-stage is in place)
Shipping is however fairly expensive from Norway...

regards
Arne K
cobra2-at-online-dot-no
 
This is the detail for a 2005 Joseph Chow upgrade to a T-9090 II that is now on eb*y. I interpreted this from one of the images in the auction, rather than link to a listing that will be gone in a month.

1) 'Upgrade wiring' to 16 AWG Hi-Q silver plated copper wires for power cord; upgrade to Wattgate plug
2) 'Upgrade wiring' between line filter
3) 'Upgrade wiring' between power transformer and ac switch
4) 'Upgrade wiring' between PCBs and output jacks
5) Upgrade IF ladder PCB at position X151 with 3 150 khz IF filters
6) Upgrade four rectifier diodes to fast speed soft recovery low noise diodes
7) Upgrade C211, C317, and C318 to 47uf/16v Blackgate caps
8) Upgrade power caps to 2200uf/50v Nichicon caps
9) Remove C904, C905, C906, C924, and R901
10) Upgrade Q204, Q301, and Q311 to BurrBrown OPA2134P
11) Upgrade output jacks to Teflon RCAs
12) Align sensitivity, THD, separation, 19khz leakage, and meter calibration

Item number: 190537584412

I'm thinking doing about several parts of this upgrade. So after removing C904, C905, C906, C924, and R901, would one want to leave jumpers in their places or leave nothing? If it should be obvious that jumpers should be installed, then excuse me.
 
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I have a 9090-II lying around...can sell the internals for reasonable cost.
(it has a few missing components, of the most common types, all big IC's & processor & input-stage is in place)
Shipping is however fairly expensive from Norway...

regards
Arne K
cobra2-at-online-dot-no

You have a PM

cheers
 
Hello all sorry for bumping this old thread. I have a T-9090 and lost the preset button "2/12" while moving. Very bummed. Does any one have this part? Also are there any other tuner that uses the same buttons for preset?

Thanks
 
It might be a common switch that you can find a replacement for, but I do not know until I see it. See what its physical dimensions are and search Mouser/Digi-key or other disti to see if you can find a match. yes it requires you to take it all apart to check out the switch, it can be a PITA, I do not know, I have never taken one apart. The service manual might have more info, I'd have to check it out.
 
He needs the button, not the switch. No way that will be a common replacement part and unlikely it'll be shared by other models, though I suppose could try one of the other 9090 versions or next tuner down in the 9090 series etc.

John
 
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