I had a Sony 777ES back in the day and it did not do a good job with Redbook CDs, but it was an SACD player. ;-)
Vintage CD Players
- Thread starter ejfud
- Start date
Back when I messed with them...I found that the Sony and Oppo SACD players sounded flat to near dreadful with Redbook discs.
Couldn't help but feel it was by design too to ensure that the SACD discs would always sound better by comparison.
AND ensure the sale of new SACD discs!
Couldn't help but feel it was by design too to ensure that the SACD discs would always sound better by comparison.
AND ensure the sale of new SACD discs!
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As mentioned in another thread, I just picked up a Philips CD50 over the weekend (CDM-4/19 transport + TDA1541A DACs) which is probably suitably vintage.
(stock internet photo - not my actual player)
(stock internet photo - not my actual player)
My brother has one of those....the plastic gears in the transport have rotted away.
I couldn't afford this Magnavox CDB650 reviewed in the March '87 Audio issue, then. Walt Jung wrote an article on how to modify these machines in the June '87 Audio which served as a template for DIYers on how to modify digital machines.
@je2a3 - I just happened to stumble across a near-mint Magnavox CDB650 for half a Benjamin today (I know I'm on a fiscal diet, but one does not pass up this sort of opportunity).
(testing it out with a little Brandi Carlile The Story in the photo above)
So are op-amp upgrades + recap the recommended diet for these players?
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Congrats!
If you want to play with it and not do anything irreversible, I suggest getting sockets for the op-amps in the audio section, the SAA7220P and perhaps the TDA1541.
What I did to my CDB465 would be my recommendation:
1. I don't do across the board PS re-cap. But I pull them out to check for bulging.
2. I didn't go beyond OPA2604 + WIMAs (2 x red rectangular caps above) in the output section because after researching the topology of op-amps they're typical high negative feedback circuits with great specs but IME, not good for the organic SET/Altec sound I prefer. Given the prices asked for boutique op-amps and the discrete variety, I could get a TDA1541 DAC board, bypass the op-amp/IV stage and graft a simple tube output section sans NFB. Also, IMO, the metal/plastic Magnavox chassis is too cramped and flimsy to build a proper tube output I/V stage.
3. To my ears going NOS gave more of the organic sound I crave for than the OPA2604/WIMA upgrade. Since I didn't want to cut traces ala Lampizator, I carefully unsoldered the SAA7220P, installed a socket and ordered the $30 module from the Eastern European seller on eBay. The 3 jumper wires in my blog only works on outboard DACs not on CD players. But keep the SAA7220P handy because the digital coax output will not work without it.
4. I did all the above mods to my CDB650 which I use as a transport now, so the SAA7220P is back in place. But to my ears it sounds better as a CD-T w/o the TDA1541. That's the reason I also installed a socket for the TDA1541.
Happy listening!
1tumbleweed
Junior Member
LHH1000! Nice to know some of those are still out there kickin'. I had a CD80 for years, finally sold it for silly money because it needed work I couldn't handle. Its replacement, an Onkyo DX-706, is no slouch either.
Does the NOS conversion take the output directly off the TDA1541 (e.g. no analog reconstruction filtering to remove ultrasonics) like the Lampizator conversion?Congrats!
If you want to play with it and not do anything irreversible, I suggest getting sockets for the op-amps in the audio section, the SAA7220P and perhaps the TDA1541.
What I did to my CDB465 would be my recommendation:
1. I don't do across the board PS re-cap. But I pull them out to check for bulging.
2. I didn't go beyond OPA2604 + WIMAs (2 x red rectangular caps above) in the output section because after researching the topology of op-amps they're typical high negative feedback circuits with great specs but IME, not good for the organic SET/Altec sound I prefer. Given the prices asked for boutique op-amps and the discrete variety, I could get a TDA1541 DAC board, bypass the op-amp/IV stage and graft a simple tube output section sans NFB. Also, IMO, the metal/plastic Magnavox chassis is too cramped and flimsy to build a proper tube output I/V stage.
3. To my ears going NOS gave more of the organic sound I crave for than the OPA2604/WIMA upgrade. Since I didn't want to cut traces ala Lampizator, I carefully unsoldered the SAA7220P, installed a socket and ordered the $30 module from the Eastern European seller on eBay. The 3 jumper wires in my blog only works on outboard DACs not on CD players. But keep the SAA7220P handy because the digital coax output will not work without it.
4. I did all the above mods to my CDB650 which I use as a transport now, so the SAA7220P is back in place. But to my ears it sounds better as a CD-T w/o the TDA1541. That's the reason I also installed a socket for the TDA1541.
Happy listening!
Also, I'd read in a couple of places that very high slew-rate op-amps (e.g. something like an AD827JNZ with a 300V/µs slew-rate) are a good option if you are going as far to replace in CD Players / DACs, although I'm not sure what are considered optimal slew-rates (e.g. not too low, not too high). I see the OPA2604 has about a 3.5x higher (25 V/µs vs 7 V/µs for the original op-amp). Any thoughts on this? Waste of effort?
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Based on schematics I've seen, the SAA7220P chip (which performs 4 x oversampling + filtering) precedes the TDA1541 D/A converter chip, thus if the SAA7220P is removed, no more 4x oversampling (NOS) and no ultrasonic filter.
AFAIK, analog reconstruction happens inside the TDA1541 digital to analog converter chip.
TDA1541 block diagram
Pins 6 & 25, right and left channel analog outputs + the op-amp based analog outputs are highlighted in red
To put it simply, the output voltage from pins 6 and 25 is miniscule and needs further amplification. Philips decided to use an op-amp based audio amplifier section (essentially the equivalent of a line level preamp) in their CDPs. Cheaper and easier to manufacture but does it offer the best sound possible?
Since the '80s op-amp specs have improved exponentially. However, I don't know how those specs relate to sound. All I know is, my favorite 6SN7 from the '40s will definitely pale in comparison to an '80s 5532 op-amp on paper. I also know that op-amps need some form of corrective negative feedback (see 2.2nF cap + 1.8K resistor in the block diagram) to achieve circuit stability and good numbers while my humble 6SN7 twin triode doesn't and can quite possibly sound much better.
That said, this was the result of my rather limited op-amp/OS vs. NOS rolling:
1. The most organic sound I heard from the CDB465/650 was using the $30 Eastern European NOS/reclock module + OPA2604/WIMAs.
2. NOS/Reclock module + stock LM833 or 5532/WIMAs.
3. Stock 4x OS + OPA2604/WIMAs was just a different sound IMO (vs. LM833/5532), perhaps a hint of tubey sound due to the FETs (?) inside the OPA2604 but I'd hesitate to call it a true upgrade in spite of the much better specs.
Instead of going further and investing on faster slew rate op-amps and the discrete variety, which will all soon become obsolete, I bought a first generation (late '80s) Arcam Delta Black Box DAC with a Class A discrete solid-state audio stage after the TDA1541. After several months of listening comparisons, I preferred the sound of the NOS'd TDA1541 Arcam with discrete output stage over the Adcom GDA 600 (op-amps in the analog out) and Audio GD R2R 11 (discrete R2R + solid state outputs). That's what convinced me to DIY my nosTDA1541tubedac.
I wrote this long winded reply to show that a DIY DAC of your choice (AD1865, Burr-Brown PCM kits, etc. on eBay) might be a better route for somebody with your DIY background rather than getting stuck in an op-amp rolling rabbit hole.
Yes...yes it does.
I have been tempted by something like that (actually, I'm tempted by an AD1865 Pi hat, but can't afford right now), although in theory, I could just plug this Magnavox via SPDIF into my current GDA-600. However, I figured I'd try it out au natural for a while first (albeit with some strategic recaps since I'm sure that it's not entirely in spec).
My previous reply should've been, "I can justify spending $10-20 for op-amps (sourced from reputable US sellers only) and sockets for fun and experience" instead of the "big picture." 😊
Happy tinkering!
Yep. Although it seems eBay is the only place to find OPA2604 op-amps now.
I got mine from juried_engineering_IIc but I don't see 2604s anymore...IIRC, they were about 4.50/each + shippingYep. Although it seems eBay is the only place to find OPA2604 op-amps now.
tevatronix has 2604s at a similar price, but 8 negatives in the past month can be discouraging, FWIW, I've ordered super capacitors from them and had no issues.
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