Hmmmm I've wired the circuit as shown, but for some reason it's not cutting out when the player is turned off.
When powered the green light is 'on' and when it plays that light goes off, so it is switching in response to playback.
It's just not behaving as I'd like. I'd like audio blocked to the RCAs unless the CD player (relay) is powered so there is no power-down crackle noise if that makes sense.
The only thing I didn't have to hand is the resistors you used (47 ohm). Is the issue? Could the issue be where the location I earth the relay?
Any help appreciated. Otherwise, I'll call it a day and put the machine back together for a good while.
When powered the green light is 'on' and when it plays that light goes off, so it is switching in response to playback.
It's just not behaving as I'd like. I'd like audio blocked to the RCAs unless the CD player (relay) is powered so there is no power-down crackle noise if that makes sense.
The only thing I didn't have to hand is the resistors you used (47 ohm). Is the issue? Could the issue be where the location I earth the relay?
Any help appreciated. Otherwise, I'll call it a day and put the machine back together for a good while.
It seems there is something wrong with your relay control signal. When a CD track is played the green light should be on and when a CD is stopped the green light should be off.
All done 
Removed the entire analogue section all the way back to the DAC pins (including the regs and the TX connections). Got separate regs with local bypass caps on the pins and a star ground point. Coax cable for the HF from the servo PCB. Copper shielded all chips and grounded them to the chip pins. Separate 50VA tx for 5V supply, leaving the donated 6000KI tx to power the microprocessor and display only.
These latest mods have cleared up the last drops of noise from the system now. A lot of changes but the results were not huge. I still maintain that for the CD67 Rays original mods list made the biggest improvement in sound quality. Adding a super clock 4S, replacing analogue section with fine silver audio transformers and adding super regs made another step improvement.
Player sounds unreal now. Like the nicest vinyl you've ever heard but without the hiss and pops.
Thank you everyone for the monumental thread,!!
Removed the entire analogue section all the way back to the DAC pins (including the regs and the TX connections). Got separate regs with local bypass caps on the pins and a star ground point. Coax cable for the HF from the servo PCB. Copper shielded all chips and grounded them to the chip pins. Separate 50VA tx for 5V supply, leaving the donated 6000KI tx to power the microprocessor and display only.
These latest mods have cleared up the last drops of noise from the system now. A lot of changes but the results were not huge. I still maintain that for the CD67 Rays original mods list made the biggest improvement in sound quality. Adding a super clock 4S, replacing analogue section with fine silver audio transformers and adding super regs made another step improvement.
Player sounds unreal now. Like the nicest vinyl you've ever heard but without the hiss and pops.
Thank you everyone for the monumental thread,!!
Attachments
No.
It's that small-value, low-ESR capacitors cause regulators to oscillate in the audio band; and adding larger amounts of low-quality capacitance outweighs or swamps this effect.
Here's a primer.:
Using 3-pin regulators off-piste: part 3
- it's based on the LM317 but all regs using feedback exhibit this effect to some extent. Be aware the newer LDO types have other sensitivities to this parameter also, owing to the way they work... you must always read the datasheet.
Next time you read someone added 100+uF at the opamp pins and it sounded better, and you should too - means they can't design or use regulators
Last edited:
(just reading my last line back it seems a bit snarky, not the spirit meant!)
Just to add - the other brute-force way to stop caps interacting with a regulator's output impedance is to use a resistor between the two, small-value, acts like RC filter on the output of the reg. Marantz of course did this in the cd63 output stage, where you see 10 ohms before those 220uF stargets. Now you know why. It stops one interaction, but creates another - now the opamp doesnt 'see' a very low impedance supply, so signal-related artifacts on the supply rails increase ...pick your compromise!
Just to add - the other brute-force way to stop caps interacting with a regulator's output impedance is to use a resistor between the two, small-value, acts like RC filter on the output of the reg. Marantz of course did this in the cd63 output stage, where you see 10 ohms before those 220uF stargets. Now you know why. It stops one interaction, but creates another - now the opamp doesnt 'see' a very low impedance supply, so signal-related artifacts on the supply rails increase ...pick your compromise!
Thanks Martin & Ben.
Some highlights from the LT1086 datasheet:
"The LT1086 is pin compatible with older 3-terminal adjustable
regulators. A minimum 10uF output capacitor is
required on these devices.
The LT1086 offers excellent line and load regulation specifications
and ripple rejection exceeds 75dB even at the
maximum load current of 1.5A."
For all operating conditions, the addition of
150uF aluminum electrolytic or a 22uF solid tantalum on
the output will ensure stability.
For fixed voltage devices or adjustable devices
without an adjust pin bypass capacitor, smaller output
capacitors can be used with equally good results.
Recommended Capacitor Values
INPUT || OUTPUT || ADJUSTMENT
10uF || 10uF Tantalum, 50uF Aluminum || None
10uF || 22uF Tantalum, 150uF Aluminum || 20uF
Output capacitance
can be increased without limit and larger values of
output capacitor further improve stability and transient
response of the LT1086 regulators.
Some highlights from the LT1086 datasheet:
"The LT1086 is pin compatible with older 3-terminal adjustable
regulators. A minimum 10uF output capacitor is
required on these devices.
The LT1086 offers excellent line and load regulation specifications
and ripple rejection exceeds 75dB even at the
maximum load current of 1.5A."
For all operating conditions, the addition of
150uF aluminum electrolytic or a 22uF solid tantalum on
the output will ensure stability.
For fixed voltage devices or adjustable devices
without an adjust pin bypass capacitor, smaller output
capacitors can be used with equally good results.
Recommended Capacitor Values
INPUT || OUTPUT || ADJUSTMENT
10uF || 10uF Tantalum, 50uF Aluminum || None
10uF || 22uF Tantalum, 150uF Aluminum || 20uF
Output capacitance
can be increased without limit and larger values of
output capacitor further improve stability and transient
response of the LT1086 regulators.
No mention is made of using very small bypass caps like 0.1uF, but perhaps you're right and I should stick to exactly what the datasheet says rather than trying to be smarter than the electronics engineers at LT! I have the 5V fixed voltage version of the chip so I could use 50uF rather than 150UF on the output..
Dammit...in my ignorance, I assumed low-ESR was the way forward for anything to do with power supplies. Perhaps I'd be best using a 22uF Tantalum on the output?
Next time you read someone added 100+uF at the opamp pins and it sounded better, and you should too - means they can't design or use regulators
I can't design regulators, and I can only barely use them thanks to the good advice of contributors like you, Martin. I have a good year of happy listening under my belt with 10 of the LM317s done like you describe. I have 22uF tantalums at the regulator outputs as recommended, then short wires to 470uF Black Gates at the load.
I haven't been listening as much since I did my DOS though. I think the poor quality regs on that might be to blame.
Hi all
Been slowly ploughing through the mountain of information in this epic thread! Being an IT person and a bit of an electronics 'meddler' i fear i may have been bitten by the bug! I have a 67SE which has served me faithfully for many many years; recently the laser has started failing to read discs, so a replacement VAM unit has been bought to give it a new lease of life - and whilst looking for info on replacing the unit, i came across the incredible amount of information about modding this player!
I've purchased some gold plated socket and a couple of different option op amps to begin with - some OPA2604 and some LM6172 to see what the difference is in sounds quality.
I've been looking at Ray's first mod lists for 57 and 67OSE players (are there any updated ones or are the first ones the most recent?) and i want to try and do some more "adjustments" I don't want to spend a fortune as the rest of the system probably wouldn't do it justice and i would end up buying ridiculously expensive kit to compliment it - much to the other half's annoyance
I was planning on bypassing the HDAM, replacing the RCA sockets, replacing the compnents round the OpAmps with higher quality components (can i use metal film 0.1% tol resistors or are the welwyn surface mount options better?), and replacing the standard regulators with a better option (suggestions appreciated!) - and also using one of the tentlabs DIy clocks with the power supply circuit they have on their site to replace the standard one.
Does this all sound good - and is there any specific order anyone would suggest; is the tentlabs clock a good choice or should i just do the clock hack instead (can someone please advise what cap i use on the DAC, i.e a farnell code...looking at the options i was a little confused as to the best choice for this) - or both?
IS it worth fitting a separate regulator "bank" to separate the dac power supplies, and if so what would everyone recommend as a replacement these days?
Sorry for all the questions - i'm trying to pick my way through everything at the moment, but it's a lot to digest
Been slowly ploughing through the mountain of information in this epic thread! Being an IT person and a bit of an electronics 'meddler' i fear i may have been bitten by the bug! I have a 67SE which has served me faithfully for many many years; recently the laser has started failing to read discs, so a replacement VAM unit has been bought to give it a new lease of life - and whilst looking for info on replacing the unit, i came across the incredible amount of information about modding this player!
I've purchased some gold plated socket and a couple of different option op amps to begin with - some OPA2604 and some LM6172 to see what the difference is in sounds quality.
I've been looking at Ray's first mod lists for 57 and 67OSE players (are there any updated ones or are the first ones the most recent?) and i want to try and do some more "adjustments"
I don't want to spend a fortune as the rest of the system probably wouldn't do it justice and i would end up buying ridiculously expensive kit to compliment it - much to the other half's annoyance I was planning on bypassing the HDAM, replacing the RCA sockets, replacing the compnents round the OpAmps with higher quality components (can i use metal film 0.1% tol resistors or are the welwyn surface mount options better?), and replacing the standard regulators with a better option (suggestions appreciated!) - and also using one of the tentlabs DIy clocks with the power supply circuit they have on their site to replace the standard one.
Does this all sound good - and is there any specific order anyone would suggest; is the tentlabs clock a good choice or should i just do the clock hack instead (can someone please advise what cap i use on the DAC, i.e a farnell code...looking at the options i was a little confused as to the best choice for this) - or both?
IS it worth fitting a separate regulator "bank" to separate the dac power supplies, and if so what would everyone recommend as a replacement these days?
Sorry for all the questions - i'm trying to pick my way through everything at the moment, but it's a lot to digest
Hi bigi,
Before you spend time and money on nice parts for your output stage, it's probably worth soul searching whether you are likely to end up with a DOS or output transformers instead. If so, you might be better off jumping straight into those options.
A low jitter clock is definitely worthwhile. If you want a DIY solution, I can definitely recommend going with the Flea. For plug-and-play, Fidelity Audio's clocks come well recommended.
Ben
Before you spend time and money on nice parts for your output stage, it's probably worth soul searching whether you are likely to end up with a DOS or output transformers instead. If so, you might be better off jumping straight into those options.
A low jitter clock is definitely worthwhile. If you want a DIY solution, I can definitely recommend going with the Flea. For plug-and-play, Fidelity Audio's clocks come well recommended.
Ben
Hi Ben
Thanks for the options - like i say I don't think i want to start making massive changes like a DOS, multiple external PSUs etc - apart from then wanting to spend more of other parts of my system - I dont think the OH would be too happy with any more electronics taking over our front room
I don't really want to be spending £££s on clocks, so happy to build one myself - likely to be the Flea DIY kit, together with a tentlabs crystal and a separate psu (if i can find one to fit in the case for it)
With regards to output stage - i would imagine replacing it with output transformers would be a very expensive option?
Thanks for the options - like i say I don't think i want to start making massive changes like a DOS, multiple external PSUs etc - apart from then wanting to spend more of other parts of my system - I dont think the OH would be too happy with any more electronics taking over our front room
I don't really want to be spending £££s on clocks, so happy to build one myself - likely to be the Flea DIY kit, together with a tentlabs crystal and a separate psu (if i can find one to fit in the case for it)
With regards to output stage - i would imagine replacing it with output transformers would be a very expensive option?
If you want to go it cheap. I would suggest you disable the HDAM and change the 2 opamps to 4562. You will notice a big jump in SQ. If possible change all the caps around the opamps to better quality caps.Hi Ben
Thanks for the options - like i say I don't think i want to start making massive changes like a DOS, multiple external PSUs etc - apart from then wanting to spend more of other parts of my system - I dont think the OH would be too happy with any more electronics taking over our front room
I don't really want to be spending £££s on clocks, so happy to build one myself - likely to be the Flea DIY kit, together with a tentlabs crystal and a separate psu (if i can find one to fit in the case for it)
With regards to output stage - i would imagine replacing it with output transformers would be a very expensive option?
@highlander would these be a better option than the OPA2604 or LM6172 i have seen recommended elsewhere?
Also, when i fit the Flea kit, can i only run the DAC off it? I notice there are two outputs...
Also, could someone point me in the direction of a suitable power supply module i can use to run the flea? struggling to find something at the usual places!
thanks guys
Also, when i fit the Flea kit, can i only run the DAC off it? I notice there are two outputs...
Also, could someone point me in the direction of a suitable power supply module i can use to run the flea? struggling to find something at the usual places!
thanks guys