The 2604 sounds like junk!
I've replaced all 3 of the duals on the input to my amp and it sounds like a different beast!
2 of them are LME47920HA and 1 is normal DIL.
Its transformed it. Those opamps are just awesome for the bucks.
The only way to go better is discrete (Burson) IMHO
I'm now working on the 604 (single ver of the 2604) replacing them (1 per channel) with bursons.
The opamp discussion will continue, but of what I've tested the LME47920HA is far superior to anything other opamp in terms of detail, openess and weight!
I've replaced all 3 of the duals on the input to my amp and it sounds like a different beast!
2 of them are LME47920HA and 1 is normal DIL.
Its transformed it. Those opamps are just awesome for the bucks.
The only way to go better is discrete (Burson) IMHO
I'm now working on the 604 (single ver of the 2604) replacing them (1 per channel) with bursons.
The opamp discussion will continue, but of what I've tested the LME47920HA is far superior to anything other opamp in terms of detail, openess and weight!
OMG!
I fitted a C2 from audioupgrades today.
I'm lost for words and its only been in about 5 hours!
Appart from the multiple outputs allowing for easy clock distribution at x1, /2 & /4 (sysclock, bitclock, and DEM clocking).......
Appart from looking absolutely amaizing with uber cool leds (we all like shiney things) for constant current........
Appart from the ultra low noise SPower regulator built in to the clock...........
It sound absolutely awesome! The sound has definately changed. The blacks are blacker and the whites are whiter. The seperation is to beheld. The sound has become smoother and more refined (to the point that I put the rubbish opamps back into my amp to make sure it was the clock making the difference!).
There is an openness and accuracy to the sound and its sooo sooo easy to listen to. The harsh edge I'd created (without realising) in chasing detail from this TDA has been tamed with no loss of resolution. Its an altogether fuller sound with all the weight you could need. I cannot fault it in any way!
I'm not sure if this design has evolved based on theory or testing but I have to say, I'd never have said that a clock could make this sort of change to the smoothness of the sound.
Ian
I fitted a C2 from audioupgrades today.
I'm lost for words and its only been in about 5 hours!
Appart from the multiple outputs allowing for easy clock distribution at x1, /2 & /4 (sysclock, bitclock, and DEM clocking).......
Appart from looking absolutely amaizing with uber cool leds (we all like shiney things) for constant current........
Appart from the ultra low noise SPower regulator built in to the clock...........
It sound absolutely awesome! The sound has definately changed. The blacks are blacker and the whites are whiter. The seperation is to beheld. The sound has become smoother and more refined (to the point that I put the rubbish opamps back into my amp to make sure it was the clock making the difference!).
There is an openness and accuracy to the sound and its sooo sooo easy to listen to. The harsh edge I'd created (without realising) in chasing detail from this TDA has been tamed with no loss of resolution. Its an altogether fuller sound with all the weight you could need. I cannot fault it in any way!
I'm not sure if this design has evolved based on theory or testing but I have to say, I'd never have said that a clock could make this sort of change to the smoothness of the sound.
Ian
Attachments
Ian,
Just to clarify, is that a thumbs up or thumbs down?
I was expecting this, after hearing Brent's and Lee's comments, and hearing one at Sercal, if only briefly. A superb product. I will get one eventually.
Simon
Just to clarify, is that a thumbs up or thumbs down?
I was expecting this, after hearing Brent's and Lee's comments, and hearing one at Sercal, if only briefly. A superb product. I will get one eventually.
Simon
Thanks Ian
The clock evolved with theory but ultimatly was tested using my ears and adjustments were made where necessary
Was it a Trichord clock 4 it replaced?
cheers
Brent
The clock evolved with theory but ultimatly was tested using my ears and adjustments were made where necessary
Was it a Trichord clock 4 it replaced?
cheers
Brent
rowemeister said:Thanks Ian
The clock evolved with theory but ultimatly was tested using my ears and adjustments were made where necessary
Was it a Trichord clock 4 it replaced?
cheers
Brent
Indeed! It was a Trichord Clock 4 and a a D1 to give me /2 for bitclock and DEM.
The clock distribution has remained unchanged i.e. individual feeds to the 2 SAA's, 2 to the TDA and 1 to the DEM which inturn feeds another 2 to the TDA (I think that makes sense!).
I left the player on repeat all night to help with burn in! I've not had a listen yet but I will very soon!
Top Top Top product Brent absolutely awesome sound, great flexibility and above all it represents outstanding value for money. I can't recommend it highly enough!
😀
Ian
Chivvyp said:
Mute functions now back.
Next question, without the 7220 I'm feeding the crystal directly to the xtal1 /xtal2 pins on the 7210. Is the xtal2 drive output to clock crystal just a permanent fixed voltage (+5V?) that I can disconnect and feed a clean(er) voltage to the clock or is there something else involved?
Thanks
Pete
Hi Lee,
Not in mine. In the 7210 datasheet XTAL2 is "drive output to clock crystal".
As I don't have 7220 chip anymore and I have the non-a 1541, the clocking is all in the 7210. I have xtal1 and 2 connected to the 2 pins of the crystal (with the original res and caps).
Regards
Pete
Not in mine. In the 7210 datasheet XTAL2 is "drive output to clock crystal".
As I don't have 7220 chip anymore and I have the non-a 1541, the clocking is all in the 7210. I have xtal1 and 2 connected to the 2 pins of the crystal (with the original res and caps).
Regards
Pete
Hi guys,
I have Philips CD951, which I don't need. This is a 950 revised, some changes in a few components. I have a complete service manual including the 950-to-951 change sheet. The unit is in stock condition and works flawlessly.
Anybody interested? Make me an offer. I'm easy 😉
Jan Didden
I have Philips CD951, which I don't need. This is a 950 revised, some changes in a few components. I have a complete service manual including the 950-to-951 change sheet. The unit is in stock condition and works flawlessly.
Anybody interested? Make me an offer. I'm easy 😉
Jan Didden
Hi everyone,
I decided to try "testing" and installing my Pass D1 output stage last night. I mounted my big Mundorf caps on the little PCB and routed my regulator outputs and ground to the new board.
I powered up the board (disconnected from the DAC at this point!) and checked for input offset. This was over -2V on each side. I adjusted the trimmer as far as it went to reach -1.8V and -1.9V.
After scratching my head a bit I realised it's not meant to work on +-12VDC but 30VDC and that must be the problem. The only quick test I could do was run it from my unregulated +-18V rails. This took the input offsets down to -0.9V and -1V. I think this answers my question as to what's wrong. So I'm now going to knock up a higher voltage psu and look at adjusting my S Power regulators to work at +-30VDC.
Simon
I decided to try "testing" and installing my Pass D1 output stage last night. I mounted my big Mundorf caps on the little PCB and routed my regulator outputs and ground to the new board.
I powered up the board (disconnected from the DAC at this point!) and checked for input offset. This was over -2V on each side. I adjusted the trimmer as far as it went to reach -1.8V and -1.9V.
After scratching my head a bit I realised it's not meant to work on +-12VDC but 30VDC and that must be the problem. The only quick test I could do was run it from my unregulated +-18V rails. This took the input offsets down to -0.9V and -1V. I think this answers my question as to what's wrong. So I'm now going to knock up a higher voltage psu and look at adjusting my S Power regulators to work at +-30VDC.
Simon
I built a new and basic psu the night before last, consisting of a 100VA 2 x 25VAC toroid, big packaged bridge and 2 x 4700uF nasty Samwha caps.
I put my 22k resistors on my S Powers and powered it all up - correct - just under +-30VDC. +-36VDC going into regs, which is on the limit.
I was now able to trim the D1's inputs to zero and connect to my DAC's outputs.
It works! It sings! A rather nice improvement and a bit of that "class A magic" type of sound. The only criticism I have is I find the bass a bit bombastic, but this could be a well-developed bass revealing an issue with my speakers that I can now hear more easily.
The naturalness, space, detail, clean treble, resonant and extended, textured bass are all positives. It's easy to recommend a Pass D1 to anyone using a TDA1541 CD player or DAC.
It did sound better after being switched on for a long time - no surprises there. Sadly I've only had a couple of quick opportunities to listen as I've been a bit busy with other things.
Eventually I'll want to change the resistors to more audiophile-friendly versions, the ceramic caps to good types, increase the idle current and upgrade the power supply.
For now it's making relaxed, natural-sounding music, and that's what the 1541A is all about for me.
Simon
I put my 22k resistors on my S Powers and powered it all up - correct - just under +-30VDC. +-36VDC going into regs, which is on the limit.
I was now able to trim the D1's inputs to zero and connect to my DAC's outputs.
It works! It sings! A rather nice improvement and a bit of that "class A magic" type of sound. The only criticism I have is I find the bass a bit bombastic, but this could be a well-developed bass revealing an issue with my speakers that I can now hear more easily.
The naturalness, space, detail, clean treble, resonant and extended, textured bass are all positives. It's easy to recommend a Pass D1 to anyone using a TDA1541 CD player or DAC.
It did sound better after being switched on for a long time - no surprises there. Sadly I've only had a couple of quick opportunities to listen as I've been a bit busy with other things.
Eventually I'll want to change the resistors to more audiophile-friendly versions, the ceramic caps to good types, increase the idle current and upgrade the power supply.
For now it's making relaxed, natural-sounding music, and that's what the 1541A is all about for me.
Simon