a.palfreyman
pfm Member
Cheers again guys. Don't worry Chartz, I'll keep an open mind and I have a completely unmodded player for comparison. 
Hope to get the Flea kit next week.
Hope to get the Flea kit next week.
Philips CD160 not working
- Thread starter a.palfreyman
- Start date
Dowser
Learning to bodge again..
Dowser
Learning to bodge again..
That’s a shame, and a bit of a waste - I’d happily pay postage to Swissieland
im one of the odd people who likes what a decent clock can do
a.palfreyman
pfm Member
Would be a shame to add to landfill.
Go on, let him have it......
Go on, let him have it......
a.palfreyman
pfm Member
Got my Flea kit from Ray's Audio in Netherlands and XO from Chevron Audio. Waiting on small TX and bits for PSU. Martin Clark very kindly sent some extras for the flea. .
Before I add the clock though, I'm going to use the extra winding on the TX to provide a stable -15V for the TDA. Be churlish not to TBH. Then I'm going to let this settle in before I add the clock.
.Before I add the clock though, I'm going to use the extra winding on the TX to provide a stable -15V for the TDA. Be churlish not to TBH.
Then I'm going to let this settle in before I add the clock.
a.palfreyman
pfm Member
PSU built: two windings @ 15Vac, 2.3VA total. 470uF/60R/470uF gives about 21Vdc with 20mV ripple at circa 30mA from each winding. Was surprised the ripple was so low but measuring the secondaries, these are about 50R so I get half the expected ripple for free. Will be a squeeze but it will just fit in the pocket adjacent to the transformer.
Martin Clark very kindly also gave me some pointers to a nice quite reg. arrangement for the -15V using a ccs to power a voltage ref and emitter follower. With 100n across the ref (two zeners and a diode in series to give -15.5V) to kill the zener noise, I get an incredibly stable -14.8V output. My scope shows it at circa 0.1 to 0.2mV ripple / noise which is only just above the noise floor of my 'scope. Also built the same type of circuit to run from the -11V that feeds the -6V reg so I also have a similarly quiet -5V for the TDA as well. Will get these fitted at the weekend and run them for a bit before adding the clock.
Will be a squeeze but it will just fit in the pocket adjacent to the transformer.Martin Clark very kindly also gave me some pointers to a nice quite reg. arrangement for the -15V using a ccs to power a voltage ref and emitter follower. With 100n across the ref (two zeners and a diode in series to give -15.5V) to kill the zener noise, I get an incredibly stable -14.8V output. My scope shows it at circa 0.1 to 0.2mV ripple / noise which is only just above the noise floor of my 'scope. Also built the same type of circuit to run from the -11V that feeds the -6V reg so I also have a similarly quiet -5V for the TDA as well. Will get these fitted at the weekend and run them for a bit before adding the clock.
martin clark
pinko bodger
Nice.
With such large series R (secondaries, and the 60ohm value) you are going to get quite a significant drop on the raw supply once you start drawing more current from it - might need to revisit down to 10ohms - but even so, that's a very quiet raw supply for little effort!
re: 100nF - its probably not doing much at all but does no harm. Zeners are actually pretty darn quiet once you run enough current through them - which is why I suggested 5mA or more. easy to add R-C filtering before any pass device the reference feeds though
Last thought: make sure there's a good-sized cap decoupling the input raw supply to the -15 / -15v 3-pin regs at the regs; way back when I was playing with this I found it made a really useful difference (prob becasue the raw supply impedance of the filter I was initially using was too high.) 100-220uF ballpark, anyway.
With such large series R (secondaries, and the 60ohm value) you are going to get quite a significant drop on the raw supply once you start drawing more current from it - might need to revisit down to 10ohms - but even so, that's a very quiet raw supply for little effort!
re: 100nF - its probably not doing much at all but does no harm. Zeners are actually pretty darn quiet once you run enough current through them - which is why I suggested 5mA or more. easy to add R-C filtering before any pass device the reference feeds though
Last thought: make sure there's a good-sized cap decoupling the input raw supply to the -15 / -15v 3-pin regs at the regs; way back when I was playing with this I found it made a really useful difference (prob becasue the raw supply impedance of the filter I was initially using was too high.) 100-220uF ballpark, anyway.
a.palfreyman
pfm Member
Martin,
Under the desired load of about 25mA for the Flea I get about 21-22V and at 33mA for the input to the -15V supply I get 20.5-21V which is ideal.
Interestingly the 100n cap reduced the noise a bit but over the next 2 hours at 8mA the noise got lower and lower until it was almost immeasurable. Might remove it to see if it makes any difference. Noted about input caps. The leads will be about 8" long due to position of TX so Ill put 100uF FRs on the Flea and reg. inputs.
Ta,
AP
Under the desired load of about 25mA for the Flea I get about 21-22V and at 33mA for the input to the -15V supply I get 20.5-21V which is ideal.
Interestingly the 100n cap reduced the noise a bit but over the next 2 hours at 8mA the noise got lower and lower until it was almost immeasurable. Might remove it to see if it makes any difference. Noted about input caps. The leads will be about 8" long due to position of TX so Ill put 100uF FRs on the Flea and reg. inputs.
Ta,
AP
a.palfreyman
pfm Member
The 100n across the 15.5V ref makes a small but noticeable difference (it's only fractions of a mV) but I put it back in.
Knocked up a 1uF film cap with a 10k resistor to one side and a 1k resistor to the other and then crock clips to the outer ends of the resistors which were connected to the output of the -15V supply. Checked that the 10k had settled to 0Vdc and then connected my sig gen across the 10k and adjusted it to give 2Vp-p swing across the 1k therefore delivering +/-1mA to the output (had to adjust the sig gen at below about 500Hz due to the cap size). This caused the output to swing a smidge under 4mVp-p or +/-2mV from 20Hz out to 500kHz. Therefore I have 2 ohms output impedance that is deathly silent.
Knocked up a 1uF film cap with a 10k resistor to one side and a 1k resistor to the other and then crock clips to the outer ends of the resistors which were connected to the output of the -15V supply. Checked that the 10k had settled to 0Vdc and then connected my sig gen across the 10k and adjusted it to give 2Vp-p swing across the 1k therefore delivering +/-1mA to the output (had to adjust the sig gen at below about 500Hz due to the cap size). This caused the output to swing a smidge under 4mVp-p or +/-2mV from 20Hz out to 500kHz. Therefore I have 2 ohms output impedance that is deathly silent.
a.palfreyman
pfm Member
Got the -15v and -5v supplies fitted to the tda1541 and got about 8 hrs in on it. Seems to have increased clarity but one thing I'm certain of is the improvement in the low treble region. Chris Rea, Road to Hell, there are cymbal sounds that were always a bit 'tch' on the CD160 but more 'tish' on the micro mega drive 3 and bushmaster ii dac. These are MUCH closer now tonally. Hope to put a few more hours on it later this week and then back-to-back it with the unmodded one. Then I will install the Flea and Clock.
Massive thanks to Martin Clark for the help with the PSUs and the 'extras' for the Flea which I built last night
Massive thanks to Martin Clark for the help with the PSUs and the 'extras' for the Flea which I built last night
Mike P
Trade: Pickwell Audio
Nice work AP.
This week I've been keeping myself busy with a 'basket case' Philips CD960 which I bought in damaged non-working condition. It's now playing well and sounding good.
No doubt I'll get shot down by the 'all capacitors are the same police' but do have a play with some different decoupling caps on the TDA1541 power supplies. The exact choice of decoupling cap really does have quite an influence on the sound. For example Silmics sound very different to Oscons.
This week I've been keeping myself busy with a 'basket case' Philips CD960 which I bought in damaged non-working condition. It's now playing well and sounding good.
No doubt I'll get shot down by the 'all capacitors are the same police' but do have a play with some different decoupling caps on the TDA1541 power supplies. The exact choice of decoupling cap really does have quite an influence on the sound. For example Silmics sound very different to Oscons.
a.palfreyman
pfm Member
Noooooo!
If it's one thing I try not to do nowadays it's keep changing stuff. By the way Mike that's not a criticism because I have experienced the same myself, I just get tired of playing about for about a month which invariably leads to thinks like fracture of cables etc. Anyway, about 5 years ago, I changed some 100n caps bypassing the tants I had on the supply pins to the opamps in my pre which is based on the Rod Elliot design, but the project number escapes me and I can't find it after a quick look at his site. It sounded slightly aggressive with edgy treble. I put 0.68uF film caps there instead and the aggressive nature was pretty much gone.
Meant to mention that in adding the two supplies, I left the decoupling caps that were fitted in place so the change was from the PSUs and nothing else.
If it's one thing I try not to do nowadays it's keep changing stuff. By the way Mike that's not a criticism because I have experienced the same myself, I just get tired of playing about for about a month which invariably leads to thinks like fracture of cables etc. Anyway, about 5 years ago, I changed some 100n caps bypassing the tants I had on the supply pins to the opamps in my pre which is based on the Rod Elliot design, but the project number escapes me and I can't find it after a quick look at his site. It sounded slightly aggressive with edgy treble. I put 0.68uF film caps there instead and the aggressive nature was pretty much gone.
Meant to mention that in adding the two supplies, I left the decoupling caps that were fitted in place so the change was from the PSUs and nothing else.
a.palfreyman
pfm Member
Before fitting the Flea, I listened to the un-modified CD160, the modified CD160 and the Drive 3 / Bushmaster II combo. Couldn't hear any notable difference between the 3 sources. Really wish I didn't suffer with Tinnitus as this does tend to mask low-level detail. One thing I did notice was that when stood next to the hifi (mid-way between the speakers) with the unmodded CD160 and nothing playing, there is audible hiss / hum. Other 2 are deathly silent, even with ear to speaker drivers. The room is also far from ideal and I can get bigger audible changes from small changes at the listening position so I have to use a 'sighting system' to try and reduce this effect to the minimum.
Flea fitted and..... same result. Wouldn't be able to tell them apart unsighted as I can't even do it sighted! I will however see how we go over next few weeks. I'll just listen to the modded CD160 and then go back to the un-modded version later as I have found that after (e.g.) some speaker tweaking it can take a few listening sessions to get the full benefit, presumable as the ears / brain adjust.
I'm also tempted to improve the front-end of the NCC200s I'm using with a reg'ed positive front end supply and bootstrapped CCS, but need to scope it first to see what is actually happening.
Mike,
How's the CD960 doing?
Really wish I didn't suffer with Tinnitus as this does tend to mask low-level detail. One thing I did notice was that when stood next to the hifi (mid-way between the speakers) with the unmodded CD160 and nothing playing, there is audible hiss / hum. Other 2 are deathly silent, even with ear to speaker drivers. The room is also far from ideal and I can get bigger audible changes from small changes at the listening position so I have to use a 'sighting system' to try and reduce this effect to the minimum.Flea fitted and..... same result. Wouldn't be able to tell them apart unsighted as I can't even do it sighted!
I will however see how we go over next few weeks. I'll just listen to the modded CD160 and then go back to the un-modded version later as I have found that after (e.g.) some speaker tweaking it can take a few listening sessions to get the full benefit, presumable as the ears / brain adjust.I'm also tempted to improve the front-end of the NCC200s I'm using with a reg'ed positive front end supply and bootstrapped CCS, but need to scope it first to see what is actually happening.
Mike,
How's the CD960 doing?
Mike P
Trade: Pickwell Audio
The CD960 is now fully working and has been put into my dining room system (Creek CAS4040 S3 and tweaked Diamonds). I'm resisting the urge to start tweaking it as I already have my modded Sony CDP-555esd, mega modded CDP-710 and Marantz CD12+DA12 to play with.
I think that brings my CD player count up to over a dozen again
I really MUST sell some before my wife notices!
martin clark
pinko bodger
@a.palfreyman
That's a proper, honest view
Will look forward to one in same vein when you have more time.
(NB: let the 'flea' run anyway - it was noted by others first time round, and I agreed - nr 15yrs ago! - that things change/settle in first 12-24hrs of run-up.)
But that's a side note. Please do let us know what you think, when you are ready: good, bad, or indifferent.
That's a proper, honest view
Will look forward to one in same vein when you have more time.
(NB: let the 'flea' run anyway - it was noted by others first time round, and I agreed - nr 15yrs ago! - that things change/settle in first 12-24hrs of run-up.)
But that's a side note. Please do let us know what you think, when you are ready: good, bad, or indifferent.
a.palfreyman
pfm Member
@a.palfreyman
That's a proper, honest view
Will look forward to one in same vein when you have more time.
(NB: let the 'flea' run anyway - it was noted by others first time round, and I agreed - nr 15yrs ago! - that things change/settle in first 12-24hrs of run-up.)
But that's a side note. Please do let us know what you think, when you are ready: good, bad, or indifferent.
No point being otherwise TBH. I do think my hearing and room anomalies 'could' play a part in this but I'll never know unless I borrow some 'golden ears' at some point.
The CD960 is now fully working and has been put into my dining room system (Creek CAS4040 S3 and tweaked Diamonds). I'm resisting the urge to start tweaking it as I already have my modded Sony CDP-555esd, mega modded CDP-710 and Marantz CD12+DA12 to play with.
I think that brings my CD player count up to over a dozen again
Was it Miles Davis that said to John Coltrane 'well put the damned thing down then' or some such?
a.palfreyman
pfm Member
5 hrs today (taken some leave before Christmas) and there 'seems' some improvement (I didn't do any back-to-back listening though) but some parts of Return to Forever, Romantic Warrior sounded more subtle whilst other parts seemed more dynamic than I remember. Note to self, patience is a virtue and listen to Martin Clark!
a.palfreyman
pfm Member
Got the bits for a pair of front end +ve supplies for the NCC200 so will be doing surgery on the amp at the weekend. Will also bootstrap the LTP CCS whilst in there. Hopefully that should allow me to better confirm my suspicions over the improvements from Flea / clock which so far seems to be a slight overall improvement in clarity across the entire frequency range.