Have never heard of Phonon to be honest 
but looking at your picture I would guess a class D switching amp judging by those ferrite components. Four similar channels... PSU can't really say without seeing up close.
Without seeing a circuit it's hard to say for sure...
As I mentioned earlier you can't always just swap opamps and "get away with it" I wonder whether the opamps here are used as more than just linear gain blocks.
With it appearing to be a Class D amp they may be part of the "switching" part of the amp... perhaps triangle wave generation/comparator etc. The OPA627 is just so high speed a device it may have unwanted problems if this is the case.
Really need to see a circuit to say for sure.
I don't think you have a PSU issue though. Have you measured the supply to the opamps, pins 4 and 8 of the dual package or pins 4 and 7 on the single IC's.
but looking at your picture I would guess a class D switching amp judging by those ferrite components. Four similar channels... PSU can't really say without seeing up close.Without seeing a circuit it's hard to say for sure...
As I mentioned earlier you can't always just swap opamps and "get away with it" I wonder whether the opamps here are used as more than just linear gain blocks.
With it appearing to be a Class D amp they may be part of the "switching" part of the amp... perhaps triangle wave generation/comparator etc. The OPA627 is just so high speed a device it may have unwanted problems if this is the case.
Really need to see a circuit to say for sure.
I don't think you have a PSU issue though. Have you measured the supply to the opamps, pins 4 and 8 of the dual package or pins 4 and 7 on the single IC's.
Hi
In the country created a mini-USB DAC OPA604 for I / V STAGE products are used. Which means that I'm okay, as it sounds.
NE5534 think it's okay, but just to get only part of OPAMP than I / V STAGE PCB wiring, or the quality of power supply it is important to think.
Above-mentioned products include a differential operation, OPAMP OPA827 is used.
In the country created a mini-USB DAC OPA604 for I / V STAGE products are used. Which means that I'm okay, as it sounds.
NE5534 think it's okay, but just to get only part of OPAMP than I / V STAGE PCB wiring, or the quality of power supply it is important to think.
Above-mentioned products include a differential operation, OPAMP OPA827 is used.
Hi Mooly,
This is an expensive USD3k class A 4X60W ZeroFeedback car amplifier even back in mid 90s that runs pretty hot and certainly not Class D. My understanding is that they should be for the preamp as the right side are straight from the RCA line inputs:
http://www.diyaudio.com/forums/car-audio/140987-help-identify-capacitor-functionality.html
Yes, will proceed with OPA2107AP which I had just received for the "proof in the pudding" while waiting for the browndog adaptor for the OPA1642 recommended by Andrea to compare but wary on soldering/desoldering lest damaging the multi-layered board.
Thanks again for sharing and any advice on recommended AD op amp with 4-5mA input and manageable speed of 4-5MHz like the original NJM353D would be great as it may help to provide some sparkle to this great and warm sounding car amplifier and not overly "warm" it with the typical feedback of BB op amp being warm, slowing sound etc..
regards,
Richard
This is an expensive USD3k class A 4X60W ZeroFeedback car amplifier even back in mid 90s that runs pretty hot and certainly not Class D. My understanding is that they should be for the preamp as the right side are straight from the RCA line inputs:
http://www.diyaudio.com/forums/car-audio/140987-help-identify-capacitor-functionality.html
Yes, will proceed with OPA2107AP which I had just received for the "proof in the pudding" while waiting for the browndog adaptor for the OPA1642 recommended by Andrea to compare but wary on soldering/desoldering lest damaging the multi-layered board.
Thanks again for sharing and any advice on recommended AD op amp with 4-5mA input and manageable speed of 4-5MHz like the original NJM353D would be great as it may help to provide some sparkle to this great and warm sounding car amplifier and not overly "warm" it with the typical feedback of BB op amp being warm, slowing sound etc..
regards,
Richard
Hmmm, so the PCB on the left will be all PSU (switching) and the amp is all analogue
Andrea knows my views on just swapping opamps without knowing the circuit details of what is around it... at the very least you really need to back up what you do with tests.
Find out why those devices didn't work well.
If it is a true multilayer PCB (I don't mean just double sided) then be very careful working on it.
Andrea knows my views on just swapping opamps without knowing the circuit details of what is around it... at the very least you really need to back up what you do with tests.
Find out why those devices didn't work well.
If it is a true multilayer PCB (I don't mean just double sided) then be very careful working on it.
OK.... Now we are on page 5, in yet another op-amp replacement thread. Until now, I have not seen any discription of what you uys are searching.
It's like asking: What is the best car for me??? Well... depends on what you expect of it. People carrier or sportscar??
Without any doubt, the cheap and old NE5534 is one of the absolute most neutral op-amps you will find out there.
If you feel the need to change it, you must be looking for something that will change the original recording. But before doing that, you must decide what way to go.
What ae you searching. As long as you don't even know that, you are clearly just looking to change the op-amp, and not that concerned about how it will change the sound. Maybe then, you should ask your self, if you are into sonic performance, or if you are one of these guys who will read the datasheet to see if you like the sound of it
It's like asking: What is the best car for me??? Well... depends on what you expect of it. People carrier or sportscar??
Without any doubt, the cheap and old NE5534 is one of the absolute most neutral op-amps you will find out there.
If you feel the need to change it, you must be looking for something that will change the original recording. But before doing that, you must decide what way to go.
What ae you searching. As long as you don't even know that, you are clearly just looking to change the op-amp, and not that concerned about how it will change the sound. Maybe then, you should ask your self, if you are into sonic performance, or if you are one of these guys who will read the datasheet to see if you like the sound of it
Hi Mooly/Andrea,
Good news! Put in the 2nd amp (modded 3 for my car setup) with dual OPA627 which had been running 24/7 for the last 3 weeks in place of the NJM353D to drive the highs and midrange, shifted the previous to drive the midbass and my entire setup sounded exactly what many said of it .... extremely clean sounding, detailed and very transparent. Top-hat, cymbal etc. sounds so clear and transparent ... to the effect of being slightly bright ... details are as usual ... not dark or slow now. This is probably also "helped" by population of 8 pcs of 10uF 50V Blackgate N capacitors in place of Nichicon NP BP as input coupling capacitors and 4 pcs of the same to replaced Nichicon Polar FA which should be for some bypass function. Comparatively, the original amp was veiled although nicely veiled sounding due and it should even be better after some EQ since the previous tuning is for the original amps. However, I can also understand Andrea's comment on OPA627 being sterile (overly clinical due to it clean sounding nature) since I believe it can be if not match with warm sound equipment as in my case of Class A, Zero Feedback topology amp. I think I will need to run-in the 1st modded amp for another 1 weeks to achieve about 500 hours and the initial poor SQ may be due to the notoriously known "long burn-in" nature of the Blackgate N caps !! A-B is done with another 3 Phonon amp refurnished in all original Nichicon capacitors which had been the resident setup.
May be off topic but for understanding the slight brightness, it may be due to characteristic of main Alpine equipment:
Alpine CDA-7998R, PXA-H900, DVA-S680E, CHA-S609, TUA-T100DAB, Phonon 340C (3X), Micro Precision z-series Tweeters, Z-series Mid and SEAS reference midbass, Rainbow Vanadium 8" Sub, Belden speaker cable, Mogami IC.
Not more fiddling with op amp for now and it is tough with the PCB mounted from bottom up with the power mosfets and transistors in contact with the main single pc aluminum block chassis cum heatsink !! In conclusion, OPA627 is find for my 15 year old amps and it is a big relief ....
Thanks and regards,
Richard
Aside to Hurtig,
--------------
For the sound, I was very happy with the original NJM353 and Nichicon capacitors especially with real sounding and analog-ish vocals thru the exceptional micro-precision Z-series midrange driver. However, I always felt that clarity and transparency is somewhat lacking compared to some current top-of-range amps and setup ... hence was moved to try the OPA627 due to many reviews concluding that it is clean sounding but yet transparent review ... should be better than the "jellybean class" of dated 90s' NJM353. Regards,
Good news! Put in the 2nd amp (modded 3 for my car setup) with dual OPA627 which had been running 24/7 for the last 3 weeks in place of the NJM353D to drive the highs and midrange, shifted the previous to drive the midbass and my entire setup sounded exactly what many said of it .... extremely clean sounding, detailed and very transparent. Top-hat, cymbal etc. sounds so clear and transparent ... to the effect of being slightly bright ... details are as usual ... not dark or slow now. This is probably also "helped" by population of 8 pcs of 10uF 50V Blackgate N capacitors in place of Nichicon NP BP as input coupling capacitors and 4 pcs of the same to replaced Nichicon Polar FA which should be for some bypass function. Comparatively, the original amp was veiled although nicely veiled sounding due and it should even be better after some EQ since the previous tuning is for the original amps. However, I can also understand Andrea's comment on OPA627 being sterile (overly clinical due to it clean sounding nature) since I believe it can be if not match with warm sound equipment as in my case of Class A, Zero Feedback topology amp. I think I will need to run-in the 1st modded amp for another 1 weeks to achieve about 500 hours and the initial poor SQ may be due to the notoriously known "long burn-in" nature of the Blackgate N caps !! A-B is done with another 3 Phonon amp refurnished in all original Nichicon capacitors which had been the resident setup.
May be off topic but for understanding the slight brightness, it may be due to characteristic of main Alpine equipment:
Alpine CDA-7998R, PXA-H900, DVA-S680E, CHA-S609, TUA-T100DAB, Phonon 340C (3X), Micro Precision z-series Tweeters, Z-series Mid and SEAS reference midbass, Rainbow Vanadium 8" Sub, Belden speaker cable, Mogami IC.
Not more fiddling with op amp for now and it is tough with the PCB mounted from bottom up with the power mosfets and transistors in contact with the main single pc aluminum block chassis cum heatsink !! In conclusion, OPA627 is find for my 15 year old amps and it is a big relief ....
Thanks and regards,
Richard
Aside to Hurtig,
--------------
For the sound, I was very happy with the original NJM353 and Nichicon capacitors especially with real sounding and analog-ish vocals thru the exceptional micro-precision Z-series midrange driver. However, I always felt that clarity and transparency is somewhat lacking compared to some current top-of-range amps and setup ... hence was moved to try the OPA627 due to many reviews concluding that it is clean sounding but yet transparent review ... should be better than the "jellybean class" of dated 90s' NJM353. Regards,
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