Here are some pics from my mod.
The reg pcb houses two circuits
1) 5V rail with 5V Audiocom Invisus with coils and 3 Blackgate 16V 100uF caps powering the DAC and Decoder
2) 12V rail with 12V superreg with coils and 2 Blackgate FK 16V 100uF caps powering Audiocom superclock II.
Both circuits are fed +20V from HexFED diodes.
The reg pcb houses two circuits
1) 5V rail with 5V Audiocom Invisus with coils and 3 Blackgate 16V 100uF caps powering the DAC and Decoder
2) 12V rail with 12V superreg with coils and 2 Blackgate FK 16V 100uF caps powering Audiocom superclock II.
Both circuits are fed +20V from HexFED diodes.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
rowemeister said:Yep its all in the design. It clips on and off.
I had to design it to fit between the Headphone socket and clock too
Looks clever and well made. But headphone socket? pff!! I might load an LED into mine to look cool
Just wanna say, thanks to everyone for their encouragement, which has helped me get my player working again. If it weren't for the words of rowemeister and 6h5c, I'd have probably not got it fixed. And I'd not have plucked up the courage to measure lots of things whilst it was turned on. I've learnt a LOT about this player from poring over the service manual and following tracks around.... I can see where more mods might want to be done too, so I can break it again!
The reason I have left the socket is because I have my display pcb shielded and I need an easy point to disconnect it when removing the main pcb.
An externally hosted image should be here but it was not working when we last tested it.
Very initial hdam removal impressions
I had a brief very quiet listen last night playing Charlie Daniels, and a loud listen this morning playing Whigfield (oh yes!) and Frank Black and the Catholics.. Not much listening time yet, so take this with a large dose of sodium chloride:
On quietly, I felt the sound had greater clarity, and there was a reduction in the haze that blocks the music at low volumes.
Listening to Whigfield I felt the sound had subjectively sped up, perhaps sounding a little more 'peppy' and less weighted down.
The bass is a touch less stodgy, but still kicks hard (a relief) and low. The stereo imaging seems more distinct, and drums have more resonance.
The only possible negative is a slight bit of roughness/raggedness, which could of course easily be a revelation and not a colouration.
I will listen to the Ministry Club Classics album, as it's well mastered, but often sounded plodding in the mid to low bass. I expect an improvement here.
This mod seems to be a nice improvement, but bear in mind I also disabled the muting circuits and headphone output, and cleaned the lens and antistatic'd parts of the transport. I expect some of the improvement was cumulative from these various tweaks. And as well as the buffer I missed out a fair bit of pcb trace for the signal (see previous pic).
I had a brief very quiet listen last night playing Charlie Daniels, and a loud listen this morning playing Whigfield (oh yes!) and Frank Black and the Catholics.. Not much listening time yet, so take this with a large dose of sodium chloride:
On quietly, I felt the sound had greater clarity, and there was a reduction in the haze that blocks the music at low volumes.
Listening to Whigfield I felt the sound had subjectively sped up, perhaps sounding a little more 'peppy' and less weighted down.
The bass is a touch less stodgy, but still kicks hard (a relief) and low. The stereo imaging seems more distinct, and drums have more resonance.
The only possible negative is a slight bit of roughness/raggedness, which could of course easily be a revelation and not a colouration.
I will listen to the Ministry Club Classics album, as it's well mastered, but often sounded plodding in the mid to low bass. I expect an improvement here.
This mod seems to be a nice improvement, but bear in mind I also disabled the muting circuits and headphone output, and cleaned the lens and antistatic'd parts of the transport. I expect some of the improvement was cumulative from these various tweaks. And as well as the buffer I missed out a fair bit of pcb trace for the signal (see previous pic).
No im using the voltage from the HexFREDS D801-804 at the moment.
I have not used another TX yet. I have got this up and running and later may consider fitting dedicated TX to see what improvements there may be.
I do have a question for you though 6h5c.....
Why did you use a 47 ohm resistor to the output sockets when you did the HDAM bypass?
Did you find the final 100ohm resistor too high for the op amps output?
I have not used another TX yet. I have got this up and running and later may consider fitting dedicated TX to see what improvements there may be.
I do have a question for you though 6h5c.....
Why did you use a 47 ohm resistor to the output sockets when you did the HDAM bypass?
Did you find the final 100ohm resistor too high for the op amps output?
Re: Very initial hdam removal impressions
Hi Simon,
Good to hear you've got improvement, and that your player seems to work o.k. now. I think the bypassing of the HDAM is the biggest influence. In my experience the sound opened-up a lot. You have 4x OPA627 in there right now?
Ray.
SimontY said:
Hi Simon,
Good to hear you've got improvement, and that your player seems to work o.k. now. I think the bypassing of the HDAM is the biggest influence. In my experience the sound opened-up a lot. You have 4x OPA627 in there right now?
Ray.
rowemeister said:Well i'm about to start the bypass now
I'm curious what you find, but I bet you won't be disappointed
It's a simple mod, and the results are quite big I think.
I put in a 47R to make the output-impedance lower. It will make it easier to drive the cable. I'm going to try even lower (22R), but I have a muting relay behind it, so I don't want to short the opamp's outputs too much. Still have to look into the datasheet.
You can go as low as zero without any muting behind it, but I haven't tried it yet. I know some reports of oscillation in that situation, but that strongly depends on the opamps.
Ray.
Attachments
Re: Re: Very initial hdam removal impressions
Yo Voodoo Ray,
I expect after more settling down and burning in the sound will change a little again, but I would have to concur that the sound significantly "opens up" by removing the HDAM buffer.
4x OPA627BP, yes. These go into sockets, and 33uF/50v FC sit under each psu pin to ground of the sockets. I intend to put additional bypass caps on the Brown Dogs, as I never got around to doing that. At some point in the near future I will order some more Brown Dogs and add other combinations to try, but I don't want to ruin my current ones with bird-poo soldering. And I simply love the character of the 627 and Pany FC.
6h5c said:
Yo Voodoo Ray,
I expect after more settling down and burning in the sound will change a little again, but I would have to concur that the sound significantly "opens up" by removing the HDAM buffer.
4x OPA627BP, yes. These go into sockets, and 33uF/50v FC sit under each psu pin to ground of the sockets. I intend to put additional bypass caps on the Brown Dogs, as I never got around to doing that. At some point in the near future I will order some more Brown Dogs and add other combinations to try, but I don't want to ruin my current ones with bird-poo soldering. And I simply love the character of the 627 and Pany FC.
I may try reducing the size of the output resistors. I put 100R there because that's about what I had previously. Is it basically a case of the lower the better with this? At some point I may try a fancy resistor (but I don't expect to hear much change) or a carbon resistor, as I think I like the carbon colour. Eat me! 
Right! After listening for several hours @ work (on my amp and speaker set up used for testing) I can certainly say the HDAM bypass mod has opened up the sound further still.
On beverley knight the piano just decades away superbly.
I used silver wire (with silver loaded solder) from U210/U214 to R659/660 and used 10 ohm resistors.
I will report on my findings @ home tomorrow
On beverley knight the piano just decades away superbly.
I used silver wire (with silver loaded solder) from U210/U214 to R659/660 and used 10 ohm resistors.
I will report on my findings @ home tomorrow
SimontY said:
rowemeister said:
Hi Simon,
Meister just answered your question I guess
I changed two resistors in my loudspeaker cross-over to Kiwame carbon recently, and I was surprised by the change
(positively...)!Maybe it's worth testing a bit with different types. Common metal films can sound quite harsh i've heard, so I also put in a regular 0,25W carbon.
Ray.
rowemeister said:Right! After listening for several hours @ work (on my amp and speaker set up used for testing) I can certainly say the HDAM bypass mod has opened up the sound further still.
On beverley knight the piano just decades away superbly.
I used silver wire (with silver loaded solder) from U210/U214 to R659/660 and used 10 ohm resistors.
I will report on my findings @ home tomorrow
Glad you like it!
So the 10R works good obviously. What opamps were you using again?
I like the open sound a lot. Makes me wanna hold my breath not to interfere with the music
Ray.
6h5c said:
Hi Simon,
Meister just answered your question I guess
I changed two resistors in my loudspeaker cross-over to Kiwame carbon recently, and I was surprised by the change
Maybe it's worth testing a bit with different types. Common metal films can sound quite harsh i've heard, so I also put in a regular 0,25W carbon.
Ray.
Good evening,
Kiwame eh? Sounds fancy
I remember not liking the change in some ways when I replaced lots of the carbon ones in the output stage of the cd63 with cheap 1% 1/4w metal films. I felt the sound lost some charm or something. It's something I've been meaning to investigate.
The only series resistance in my x-overs is a little piece of resistance wire to bring the tweets down a fraction
My op amps are currently the OPA2134 but I have the OPA627 and OPA132 ready and waiting for the Browndog pcbs to arrive.
Now then....
I have listened to my cd with the reg pcb last night and talked about the gains.
Well I have been listening to the HDAM bypass mod on my system @ home.
Its brilliant!! Its added even more to every aspect of the music.
Its very open the bass is so much better over the lower frequancies.
The midrange is just breathtaking.
The treble is soooooo controlled and tight, no splashiness what so ever.
I RECOMMEND THE HDAM BYPASS MOD.
The only reservation I would have is to anyone who has done little mods. I have loads of rectification, black gate caps, clock pcb ,decent op amps etc.
So maybe it only works on heavily modded players, but thats up to you to find out.