Mod - Upgrading opamps in a yamaha av receiver

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dsiroky

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Joined 2007
#1
By and large I love my Yamaha AV Receiver. However in my music room i've just set up a pair of martin logan speakers and an external DAC (Yalong Crystal) with some LM4562's and the sound in that room is phenomenal.

That's lead me to look at whether my TV room would benefit from some op-amp upgrades - as opamps have come a long way since I bought my yamaha receiver.

That said - I'm not sure though whether it's worth the time and effort. I don't have the $ to spend on replacing it with a new high end unit - as that's going to lead me down a path of separate preamp and amps - so I thought some minor mods could improve the sound quality.

I've managed to find a schematic online for my (Yamaha RXV-1400)

http://www.epanorama.rackhost.net/s.../Receivers/Yamaha RX-V1400 Schematic Only.pdf

From reading the schematic, it appears to have several JM2068MD opamps in the circuit.

Is it worth replacing these with LM4562's? or would I need to also make modifications to other parts of the circuit - extra caps / removal of DC filtering caps.

Has anyone got experience in this area and willing to offer suggestions?
 
#4
dsiroky said:
By and large I love my Yamaha AV Receiver. However in my music room i've just set up a pair of martin logan speakers and an external DAC (Yalong Crystal) with some LM4562's and the sound in that room is phenomenal.

That's lead me to look at whether my TV room would benefit from some op-amp upgrades - as opamps have come a long way since I bought my yamaha receiver.

That said - I'm not sure though whether it's worth the time and effort. I don't have the $ to spend on replacing it with a new high end unit - as that's going to lead me down a path of separate preamp and amps - so I thought some minor mods could improve the sound quality.

I've managed to find a schematic online for my (Yamaha RXV-1400)

http://www.epanorama.rackhost.net/s.../Receivers/Yamaha RX-V1400 Schematic Only.pdf

From reading the schematic, it appears to have several JM2068MD opamps in the circuit.

Is it worth replacing these with LM4562's? or would I need to also make modifications to other parts of the circuit - extra caps / removal of DC filtering caps.

Has anyone got experience in this area and willing to offer suggestions?
Click to expand...

I have modified my RX-V2400, with better opamps. It is definately worth it. NJM2068 are really dull sounding opamps. It took me a few days to remove all the opamps and replace them with better ones. All of them are surface mount, so it is a bit tedious, but really worth it.
 
#5
I also thinking of replace my Receiver's op-amps. (Harman Kardon AVR 255).
Here is the service manual.
Same JM2068, SMD -> LM4562 (9pcs, 4,12EUR/pc), or anything else better for it?
And maybe the capacitors in the audio path (SUM 26pcs 10u/35V polarised, and 7pcs 10u/50V, 0,6EUR/6pc) to ELNA SILMIC II or Black Gate BG.
SUM cost about 61EUR (+ shipping)
And plenty of work.
Worth of it?
If the power amps not so good, i also can build some good sounding.
 
#6
bitlisz said:
I also thinking of replace my Receiver's op-amps. (Harman Kardon AVR 255).
Here is the service manual.
Same JM2068, SMD -> LM4562 (9pcs, 4,12EUR/pc), or anything else better for it?
And maybe the capacitors in the audio path (SUM 26pcs 10u/35V polarised, and 7pcs 10u/50V, 0,6EUR/6pc) to ELNA SILMIC II or Black Gate BG.
SUM cost about 61EUR (+ shipping)
And plenty of work.
Worth of it?
If the power amps not so good, i also can build some good sounding.
Click to expand...

Have you tried LM4562 in any other setup or prototype small amp?
I have tried OPA2134 and they sound beautiful. You may want to try them.

As a first step, replace the opamps and have a listen for a few days and then plan on changing the capacitors.
The power amps are good in the HK AVR 255.
 
#7
Thanks You for the recommendations!
But It seems, I already beak them.
mchabbi said:
Have you tried LM4562 in any other setup or prototype small amp?
I have tried OPA2134 and they sound beautiful. You may want to try them.

As a first step, replace the opamps and have a listen for a few days and then plan on changing the capacitors.
The power amps are good in the HK AVR 255.
Click to expand...
To be honest I never did, but one of my friend recommended, and I read many forums....and is the max what I can afford🙂

mchabbi said:
As a first step, replace the opamps and have a listen for a few days and then plan on changing the capacitors.
The power amps are good in the HK AVR 255.
Click to expand...
The thing is that much easier to replace the op-amps by removing the capacitors before...and then add the new ones.
mchabbi said:
The power amps are good in the HK AVR 255.
Click to expand...
I really hope so.
Anyway I will replace in the amp the 10uF/50V and 100uF/16V too (I think the 100uF/63V not really necessary, and really expensive from ELNA the 14pcs).
All components ordered, just waiting for them.
But maybe 3 weeks when I ready start the process.
 
#9
I really love your project ....Could you please make tutorial in how to do this??? I have the same Yamaha rx-v 1400. Youtube can be a good friend to to upload videos.

A tutorial and advice would be greatly appreciated. Thanks in advance.

Gio.
 
#10
Congrats, the soldering looks nice. I can imagine the hard work. HK receivers don't look as crowded as Yamaha ones, but I am sure it is equally hard to replace the opamps.

bitlisz said:
I just finished with the upgrade in this week.
Here are some pictures.
The sound now more transparent, detailed, accurate than before.
It was hard, but well worth of the upgrade🙂
An externally hosted image should be here but it was not working when we last tested it.
Click to expand...
 
#15
"Now which path caps can be changed?:

Are they surface-mount or thru-hole?

The simple answer is all that are in the signal path, coupling caps and the ones in the power amps' feedback loop (going to ground).

If these are surface-mount, you may not be able to do anything (for mechanical reasons).
 
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#17
See it there is a way to tack some small, say 30ga, wires on the pads of the electrolytics. You can then attach some film bypass caps to these leads.

Imagine a house with storm windows.

Imagine the storm windows are filthy dirty (electrolytic caps).

Does it make sense to replace the panes of glass (IC's) inside the house with a better grade glass?
 
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