Here's a collection of Gems I could find written by the people who know about Alpha 5 CD players. :
cut the track between Pins 2 and 4 of the TDA1541a chip - WHY ?
SAA 7220 removed altogether then connect 1 to 18 2 to 16 3 to 15 and a wire link between pins 9 and 11 - Is this OK and does this complete NON OS conversion - is there anything else that needs doing ?.
I use Black gate n series non polar for the output couplers and take the output direct from the output of the opamps to the phono sockets bypassing all those nasty muting transistors etc - Can I really do this without bypass caps and is it safe this way ?
I think it is still active when using the isolate pins 1 23 of DAC and linking 123 of filter to it.......Digital out socket - Is it still active or not ?
de-emphasis cd mode is hardly used on modern cd format, why not remove the transistors that perform this function - no one actually answered this point and wonder if this is OK to do ?
The opamp feedback resistor type has a big influence on the sound, it might be an idea to start here. Try 0.5W carbon from farnell or Audio Note tantalums. You can solder them directly onto the opamp pins to preserve the PCB tracks - The man who suggested this did not mention which resistors they are, not helpful to learners like me - does he mean R11 ?
Which pins of the op amp does he mean please ?
Any explanation welcome and indeed any useful advice too.
I've trawled this site and can only find these items on this subject.
Thanks
Andrew
cut the track between Pins 2 and 4 of the TDA1541a chip - WHY ?
SAA 7220 removed altogether then connect 1 to 18 2 to 16 3 to 15 and a wire link between pins 9 and 11 - Is this OK and does this complete NON OS conversion - is there anything else that needs doing ?.
I use Black gate n series non polar for the output couplers and take the output direct from the output of the opamps to the phono sockets bypassing all those nasty muting transistors etc - Can I really do this without bypass caps and is it safe this way ?
I think it is still active when using the isolate pins 1 23 of DAC and linking 123 of filter to it.......Digital out socket - Is it still active or not ?
de-emphasis cd mode is hardly used on modern cd format, why not remove the transistors that perform this function - no one actually answered this point and wonder if this is OK to do ?
The opamp feedback resistor type has a big influence on the sound, it might be an idea to start here. Try 0.5W carbon from farnell or Audio Note tantalums. You can solder them directly onto the opamp pins to preserve the PCB tracks - The man who suggested this did not mention which resistors they are, not helpful to learners like me - does he mean R11 ?
Which pins of the op amp does he mean please ?
Any explanation welcome and indeed any useful advice too.
I've trawled this site and can only find these items on this subject.
Thanks
Andrew
Read up on the difference between the TDA1541 and TDA1541A. It's to do with the chip clocking.
Yes. There is a lot written on Non-OS conversions for the TDA1541A. diagrams etc.
Absolutely safe. you may have some small clicks between tracks.
The digital filter does not work in NOS mode so neither does the digital out.
Yes. its OK to do.
There are other things eg power supply which would have a greater effect than the feedback resistors . I would not bother.
Andy
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Andy Hi
Hallelulah - a response - really grateful !
I was beginning to think I'd written another boring post - it happens all the time.
I have absolutely no luck whether on the chip amps section or this one.
I'm so disillusioned with this place.
So many people sign up to this, post things and then get no replies.
Then you get the members who think they know but who give unintelligable answers.
It's not for learners at all.
Rant over 😡
Thanks for reading and for the tips.
Point taken, more reading and trawling to do.
I'll do the op amp direct mod and ignore any clicks - it's a cleaner route, I like that.
Digi out - understood - I won't need off board dac if I do it right first time.
De- emphasis - great thank you.
Feedback resistors - that's what I need - straight talking.
How very refreshing - just what I wanted🙂
Many thanks
Andrew
Hallelulah - a response - really grateful !
I was beginning to think I'd written another boring post - it happens all the time.
I have absolutely no luck whether on the chip amps section or this one.
I'm so disillusioned with this place.
So many people sign up to this, post things and then get no replies.
Then you get the members who think they know but who give unintelligable answers.
It's not for learners at all.
Rant over 😡
Thanks for reading and for the tips.
Point taken, more reading and trawling to do.
I'll do the op amp direct mod and ignore any clicks - it's a cleaner route, I like that.
Digi out - understood - I won't need off board dac if I do it right first time.
De- emphasis - great thank you.
Feedback resistors - that's what I need - straight talking.
How very refreshing - just what I wanted🙂
Many thanks
Andrew
Performing the NOS mod on the SAA7220 and removing the muting transistors brings its own problems in the form of pops and clicks when idle and also track noise whilst "next-ing" or "previous-ing" or pausing. The answer here is to connect pin 23 (MUSB) of the SAA7220 to pin 18 (MUTE) of the SAA7310. This restores the player to its previous set-up, but mutes the player in the decoder rather than discretely using the transistors.
Regards
Pete
Ah great -thank you Chiivvyp.
And that means ( I think ) connecting pin 23 of the SAA7220 to the 7310 on the underside of the main board with a wire or is there a better way ?
I would prefer to use your suggestion to eliminate the click and pops
in some way.
Thanks for your time on this
Andrew
And that means ( I think ) connecting pin 23 of the SAA7220 to the 7310 on the underside of the main board with a wire or is there a better way ?
I would prefer to use your suggestion to eliminate the click and pops
in some way.
Thanks for your time on this
Andrew
The Arcam Alpha 5 is a nice player, I'd get one if it came up for sale at the right price. I've got an Alpha and an Alpha Plus, which are a very similar circuit, but with totally different PCBs.
This player is very similar to many others that use the same decoder, digital filter and DAC as this one, so you should broaden your search. Many modifications that have been done to players like the Philips CD650 and Marantz CD40 / CD50 / CD60 will apply to your Arcam.
A few things I would look into:
- Installing a DEM reclocking circuit
- Installing a low jitter clock
- Replacing the output stage (discrete solid state or tubes), or improving the one it already has (better opamps, coupling capacitors, decoupling capacitors etc.)
My only reservation about the 'NOS' mod (removing the SAA7220 digital filter) is that it will drastically increase the amount of high frequency noise the player output. You may not hear this directly, but you may cause problems in components downstream. Some amps will burn a heap of power (even to the point of destruction in very rare cases) trying as hard as they can to amplify that noise. Slew rate limiting sounds nasty.
In my opinion, a lot of the benefits of the above mod comes from removing the SAA7220 from the +5V power supply rail. It's a power hungry IC, and tends to propagate a lot of noise back into the power supply, to the detriment of the rest of the player. Consider building it it's own regulator circuit and replacing its decoupling capacitor with an ultra low impedance type (like an OS-CON).
Food for thought.
This player is very similar to many others that use the same decoder, digital filter and DAC as this one, so you should broaden your search. Many modifications that have been done to players like the Philips CD650 and Marantz CD40 / CD50 / CD60 will apply to your Arcam.
A few things I would look into:
- Installing a DEM reclocking circuit
- Installing a low jitter clock
- Replacing the output stage (discrete solid state or tubes), or improving the one it already has (better opamps, coupling capacitors, decoupling capacitors etc.)
My only reservation about the 'NOS' mod (removing the SAA7220 digital filter) is that it will drastically increase the amount of high frequency noise the player output. You may not hear this directly, but you may cause problems in components downstream. Some amps will burn a heap of power (even to the point of destruction in very rare cases) trying as hard as they can to amplify that noise. Slew rate limiting sounds nasty.
In my opinion, a lot of the benefits of the above mod comes from removing the SAA7220 from the +5V power supply rail. It's a power hungry IC, and tends to propagate a lot of noise back into the power supply, to the detriment of the rest of the player. Consider building it it's own regulator circuit and replacing its decoupling capacitor with an ultra low impedance type (like an OS-CON).
Food for thought.
Oh, and something else I remembered:
I'd leave the resistors between the opamp's output and the output connectors in place (R13 and R113). These isolate the opamp from output capacitance, without them the opamps could oscillate if you connect a pair of very capacitive interconnects. Do try removing the output shorting transistors though (Q2 and Q102), but be aware that you probably get a turn on crack and a turn off thump (that's what the transistors are there to mask).
I'd leave the resistors between the opamp's output and the output connectors in place (R13 and R113). These isolate the opamp from output capacitance, without them the opamps could oscillate if you connect a pair of very capacitive interconnects. Do try removing the output shorting transistors though (Q2 and Q102), but be aware that you probably get a turn on crack and a turn off thump (that's what the transistors are there to mask).
Many thanks
I'll do the Q2 and Q102 plus the e emphasis mod and install the Audio GD discrete output stages that I have lying around.
Do the clock and investigate the power supplies.
Anyone know where the clock attaches and which parts are to come out ?
I have an old Alpha CD player and absolutely love it - problem is the now very noisy transformer which drives me nuts.
I was told to put new cable ties around it to tighten up the wafers but it didn't work. (the small traffo to the DAC board)
Hey guys, thanks for helping me out🙂
Plenty to be thinking about
Regards
Andrew
I'll do the Q2 and Q102 plus the e emphasis mod and install the Audio GD discrete output stages that I have lying around.
Do the clock and investigate the power supplies.
Anyone know where the clock attaches and which parts are to come out ?
I have an old Alpha CD player and absolutely love it - problem is the now very noisy transformer which drives me nuts.
I was told to put new cable ties around it to tighten up the wafers but it didn't work. (the small traffo to the DAC board)
Hey guys, thanks for helping me out🙂
Plenty to be thinking about
Regards
Andrew
I would have thought it was easy to replace this transformer with a new one or similar. It's only a single +- voltage isn't it?
Pete
Not quite, it's got dual primaries and a centre tapped secondary, but nothing really special. I think I've seen someone on this forum replace it with a toroidal transformer. It doesn't worry me, both of the Alphas I've had haven't had this problem (both have had the cable tie fitted from factory though).
I'll get my meter in there and see what value of traffo I need for the Alpha..
On AA5 i've swapped the 5532's with the Audio GD Earth's - changed some caps around the output stage and removed the muting and de emphasis tranny's - it sounds a lot better, thank you.
Clock + PS next then I need to research DEM and an alterniatve I/V stage I think.
Is it lazy of me to just to fit OPA 627's for I/V - building a dedicated I/V and DEM seems beyond me really having done some research.
Maybe NOS isn't neccessary either after the warnings I've had plus the gains so far are just that - gains.
I like the simple and fast mods - less stress
Thanks to all.
Andrew
On AA5 i've swapped the 5532's with the Audio GD Earth's - changed some caps around the output stage and removed the muting and de emphasis tranny's - it sounds a lot better, thank you.
Clock + PS next then I need to research DEM and an alterniatve I/V stage I think.
Is it lazy of me to just to fit OPA 627's for I/V - building a dedicated I/V and DEM seems beyond me really having done some research.
Maybe NOS isn't neccessary either after the warnings I've had plus the gains so far are just that - gains.
I like the simple and fast mods - less stress
Thanks to all.
Andrew
Good idea. Have a look at what the unregulated DC voltage is before the regulators on the DAC board, and size it from that (convert back to AC voltage required).
Not really, my current favorite player, a Mission PCM2, just has the stock output stage with LME49720HA opamps. That was more to do with space though, the Mission is a crowded CD player.
I can't recommend using those AudioGD discrete opamps, I've seen some pretty horrible test result with those, but I guess they're worth trying if you already have them. Make sure you try some good monolithic opamps as well. Opamps like the OPA627, OPA604, OPA132, LME49710, OPA827 are worth trying (as are many more), and often it will just come down to personal taste. The most accurate opamp won't necessarily sound the best to you.
I've got 627's and 49710's and in the output stage my Audio GD Sun's wipe the floor with them - in the context of my system, my ears, choice of music and room.
Believe it or not, they all sound a bit ' shut in ' compared to these discrete units.
I'd also like to try the Lampizator o/s one day.
I've not seen test results on the Audio GD's and they may well be bad, everything can be - but I'd have them everywhere to replace op amps if I could.
I've now fitted the 627's in the i/v stage and this has improved things again.
It's now as smooth and authorative as my Alpha - y'know there's something about the plain old Alpha machine and how it sounds.
Maybe the two traffo's and strong old case ?
The Alpha's noisy PS is 24'v job according to the service manual so I'm fixing that very soon and I think I'll throw some cash at the old girl to give her a lift.
It'll probably blow the Alpha 5 away and end up back in the main system again.
Anyway, thanks again for your help and advice and...give the Audio GD's a
try, you may be surprised.
Regards
Andrew
Believe it or not, they all sound a bit ' shut in ' compared to these discrete units.
I'd also like to try the Lampizator o/s one day.
I've not seen test results on the Audio GD's and they may well be bad, everything can be - but I'd have them everywhere to replace op amps if I could.
I've now fitted the 627's in the i/v stage and this has improved things again.
It's now as smooth and authorative as my Alpha - y'know there's something about the plain old Alpha machine and how it sounds.
Maybe the two traffo's and strong old case ?
The Alpha's noisy PS is 24'v job according to the service manual so I'm fixing that very soon and I think I'll throw some cash at the old girl to give her a lift.
It'll probably blow the Alpha 5 away and end up back in the main system again.
Anyway, thanks again for your help and advice and...give the Audio GD's a
try, you may be surprised.
Regards
Andrew
best so far
I have moded to distruction a marantz 67se, philips 963sa and a arcam alpha 5. I am still using the arcam as it has the sound that I was after. Have done most of the mods to and fro that can be found on these threads. I presently have separate digital/analog transformers and supplies with lme49710 in both filter and amplify positions, with NOS. Kwak clock and mundorf sio output caps. Run this straight into the tube monos. I have tried transformer outs, and believe it or not even straight from a 100ohm I/V to the amps (not really loud enough but good). I will be trying the TL single tube output for the tda1541a he designed with very short interconnects. If you find the sound you want don't be afraid to stop and listen for a while as not all mods with take you were you want to go!!!
I have moded to distruction a marantz 67se, philips 963sa and a arcam alpha 5. I am still using the arcam as it has the sound that I was after. Have done most of the mods to and fro that can be found on these threads. I presently have separate digital/analog transformers and supplies with lme49710 in both filter and amplify positions, with NOS. Kwak clock and mundorf sio output caps. Run this straight into the tube monos. I have tried transformer outs, and believe it or not even straight from a 100ohm I/V to the amps (not really loud enough but good). I will be trying the TL single tube output for the tda1541a he designed with very short interconnects. If you find the sound you want don't be afraid to stop and listen for a while as not all mods with take you were you want to go!!!
Great
How did you do the NONOS ?
There seems to be some confusion with what needs connecting after
you've removed the SAA chip and done the links correctly.
I have had NONOS on a Alhpa 5 PLUS ( which is now completely broken :-( )
but have the DAC board here so I can copy the wire links etc.
There were absolutely no other wires needed to connect elsewhere for it to work - I liked it too, great pity.
I'd like to NONOS the Alpa 5 but am now a bit nervous to start doing it.
' run them straight into tube mono's ' - tell me about this ?
What does this mean - monoblocks, output stage like lampizator ?
I'm now comitted to upgrading my original Alpha following Simonty's lead.
Have you seen that on here ?
The Alpha is a good one and his is on another planet.
New proper toroidal traffo for DAC board is on it's way from Simonty as we speak and I've a boat load of caps to fit pronto before it gets here.
I agree with your last sentence fully - made loads of mistakes by assuming everyone else is correct in their own interpretation of sound and upgrade path.
My ears - their ears, different speakers, rooms and musical tastes.
Let me know about the tubes
Thanks
Andrew
How did you do the NONOS ?
There seems to be some confusion with what needs connecting after
you've removed the SAA chip and done the links correctly.
I have had NONOS on a Alhpa 5 PLUS ( which is now completely broken :-( )
but have the DAC board here so I can copy the wire links etc.
There were absolutely no other wires needed to connect elsewhere for it to work - I liked it too, great pity.
I'd like to NONOS the Alpa 5 but am now a bit nervous to start doing it.
' run them straight into tube mono's ' - tell me about this ?
What does this mean - monoblocks, output stage like lampizator ?
I'm now comitted to upgrading my original Alpha following Simonty's lead.
Have you seen that on here ?
The Alpha is a good one and his is on another planet.
New proper toroidal traffo for DAC board is on it's way from Simonty as we speak and I've a boat load of caps to fit pronto before it gets here.
I agree with your last sentence fully - made loads of mistakes by assuming everyone else is correct in their own interpretation of sound and upgrade path.
My ears - their ears, different speakers, rooms and musical tastes.
Let me know about the tubes
Thanks
Andrew
arcam 5 mods
I run the output of the player into the tube monoblock amps without a preamp. My amps have a level input(volume control), and they seem to have little trouble with gain. I don't believe that they sounded better with the Audible Illusion pre I have so not need to run the signal through more circuitry. Others would argue that you lose dynamic/impact, but as you know it varies from system to system.
Still working on the PS for the tube output. I will get that right first then it is a simple step to add the tube.........
I run the output of the player into the tube monoblock amps without a preamp. My amps have a level input(volume control), and they seem to have little trouble with gain. I don't believe that they sounded better with the Audible Illusion pre I have so not need to run the signal through more circuitry. Others would argue that you lose dynamic/impact, but as you know it varies from system to system.
Still working on the PS for the tube output. I will get that right first then it is a simple step to add the tube.........
I'm staring at the schematics an cant figure it out where to wire the second transformer in my Alpha 5. It's not just a plain power switch so I'm a bit confused. Can you help, please?
Regards.
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