Anton Hi
Is it you buying all the Alpha Plus models off e bay ? 😀
Good to hear from you too - loved your vintage Philips repair job on your site btw.
Brought back some memories - I had a Meridian MCD Pro years back with a Trichord clock squeezed in. It was a beauty but had another box bolted to the bottom - not sure what was inside it though. I sold it to a nutter in China for over £ 300 - good profit too 😀
I'll take some pics of my Plus tomorrow - I'm three cans into a session right now so it'd be a bit blurred if I started with the camera....
Save to say that mine is different on the power supply board to yours.
If you connect the std Alpha dark blue dac board to the plus model you'll find it does not work - I'll try and take some pics of the underside of the boards if you really want to see.
The TDA socket is a factory fit - the soldering is too good to have been a mod job.
Oh, and when I refer to the main board I mean the Philips board - not the Arcam board and....you too seem to be missing one or two caps too - same as this one.
All good fun anyway.
I didn't buy it thinking ' oh good - I got some black gates ' I got it because I want to make a tidy one with the sort of soldering that doesn't look like it's been applied with a catapult from 3 feet away....
More soon then....
Is it you buying all the Alpha Plus models off e bay ? 😀
Good to hear from you too - loved your vintage Philips repair job on your site btw.
Brought back some memories - I had a Meridian MCD Pro years back with a Trichord clock squeezed in. It was a beauty but had another box bolted to the bottom - not sure what was inside it though. I sold it to a nutter in China for over £ 300 - good profit too 😀
I'll take some pics of my Plus tomorrow - I'm three cans into a session right now so it'd be a bit blurred if I started with the camera....
Save to say that mine is different on the power supply board to yours.
If you connect the std Alpha dark blue dac board to the plus model you'll find it does not work - I'll try and take some pics of the underside of the boards if you really want to see.
The TDA socket is a factory fit - the soldering is too good to have been a mod job.
Oh, and when I refer to the main board I mean the Philips board - not the Arcam board and....you too seem to be missing one or two caps too - same as this one.
All good fun anyway.
I didn't buy it thinking ' oh good - I got some black gates ' I got it because I want to make a tidy one with the sort of soldering that doesn't look like it's been applied with a catapult from 3 feet away....
More soon then....
Your right Simon - I will eventually do away with the socket.
I'm not entirely sure we'd hear much with an S1 anyway - could be wrong of course.
I was seriously thinking about buying one but the risk is just too great. Plus £70 ish buys me a sh.. load of other stuff...
In terms of the basic topological differences between the Alpha and the Alpha+, the + model has a capacitor multiplier before the regulator and the current source biasing the DAC output is cleaner since it's fed from Q205 rather than directly from the +15V supply. Other than that there may be layout improvements and component substitutions (as mentioned before the use of BlackGates for the output coupling caps) between the two.
John, thank you - that explains the additional components then
Of course I was just about to say ' all of that ' anyway......😀 ( joke )
So... the engineers were eeking a bit extra out of it before changing the models to the Alpha 5 etc.
Great info as usual - thanks
Of course I was just about to say ' all of that ' anyway......😀 ( joke )
So... the engineers were eeking a bit extra out of it before changing the models to the Alpha 5 etc.
Great info as usual - thanks
I checked the IDC header on both my Alpha and my Alpha +, and they are the same. I did find, however, that the headers are rotated 180° relative to each other, and neither originally used shrouded headers (though I fitted one to my Alpha). It'd be easy to plug the cable in backwards without noticing that the header orientation had changed. My Alpha DAC PCB is labelled 'ALPHA CD AUDIO ISSUE A2 DEC 89', my Alpha + DAC PCB is labelled 'ALPHA CD PLUS PCB No 900403 Iss 1'.
I was referring to the Philips made mainboard. The passives I was talking about are the ones for the TDA1543's output stage that the mainboard would have had when used in a Philips player.
Ha ha, no, both of mine are from TradeMe, New Zealand's local eBay equivalent. Most of my players have come from there, the odd good player comes up on there. I bought the Alpha + about four years ago and the Alpha about three years ago.
I was referring to the Philips made mainboard. The passives I was talking about are the ones for the TDA1543's output stage that the mainboard would have had when used in a Philips player.
Ha ha, no, both of mine are from TradeMe, New Zealand's local eBay equivalent. Most of my players have come from there, the odd good player comes up on there. I bought the Alpha + about four years ago and the Alpha about three years ago.
Ooh that's cheap. very tempting to check that out, have it as a spare... hmm, money is tight though.
Interesting to see the plus. Definitely the end of model improvement just before launching the next model. I see they improved the quality of power cables to the DAC; they did away with the blue pcb - it really has weak traces; they optimized the main power supply filtering; and they really made some nice improvements to the layout of the underside with stronger ground traces and star grounding points. No wonder it got improved reviews.
What brand of caps did they use for all the 100u decoupling caps on the DAC board? Was it BG throughout? That would have been a nice touch.
Andrew, it seems you got a nice canvas to paint your masterpiece!
One day if I see one come up cheap, I might grab it to actually have a cd in addition to my DAC.
Keep in mind that neither of the two players I posted pictures of were stock. They're not modified to anywhere near the extent of other players here, but:
- Those power cables are my work, the stock ones were the same old flat grey ribbons.
- The electrolytic capacitors were all originally those light blue Rubycons, the same as all contemporary Arcam gear, except for the two output coupling capacitors, which were Blackgate STDs.
These players are a good base for modifications though, and have quite a few advantages over a normal TDA1541A based player.
- Those power cables are my work, the stock ones were the same old flat grey ribbons.
- The electrolytic capacitors were all originally those light blue Rubycons, the same as all contemporary Arcam gear, except for the two output coupling capacitors, which were Blackgate STDs.
These players are a good base for modifications though, and have quite a few advantages over a normal TDA1541A based player.
Walter Hi
It's nice to not be rushing for a change as I often did.
The original is still the benchmark and has matured beautifully.
If this new one is much better I'll be shocked but pleased.
I had no idea of the inherent layout improvements to the Plus so it's all a bit of a bonus really.
On the DAC board I've done almost all of the caps with FC's and SEPC, have 2.2 uf Vishay's on the upper MSB's, plus some styrene's and siemens stacked films underside, the metal round can LM49710's for i/v, fast soft diodes with snubber's and have ordered Shinkoh Tantalum resistors for DATA and WS ( 390R ) and six more for round the i/v op amps. CK resistor will be redundant once I've split pins 2 and 4 for clocking so I didn't need a 120R here.
I toyed with Z Foils for the 2 x 390R's but at £40 delivered it seemed a bit rediculous - I still think about this though after reading peoples feedback on what they do - the specs are eye watering to say the least.
The signal will leave the board at the i'v op amps and go to the valve buffer via silver coax.
I've a plan to suspend the dac board and increase it's mass too and once I've done some testing I'll post up how it looks.
Not sure what it'll do but I'll give it a go anyway.
My real desire is to have 4 matching oiled hardwood cheek pieces made for the two cases. Yeah, aesthetics I know...but don't you just love the look of the CD 94 and the other wood sided machines ?
All in good time - I've got plenty of that thankfully but I will do it.
This one is really about neatness, shorter raw wiring, better soldering and joints, nicer components and no repairs to tracks.
MK1 Alpha has been my education, frustration and joy in equal measure.
Mk2 will be a statement of my new found patience.
It'll also have my Alpha cased external PS connected...now that is exciting.
I know it works but I've not connected it yet - and can't imagine what it'll do to the sound.
What about you ?
Did you do anything new or are you just enjoying at the moment - it's been a while since we all communicated our mutual madness
Hope all is well
Andrew
It's nice to not be rushing for a change as I often did.
The original is still the benchmark and has matured beautifully.
If this new one is much better I'll be shocked but pleased.
I had no idea of the inherent layout improvements to the Plus so it's all a bit of a bonus really.
On the DAC board I've done almost all of the caps with FC's and SEPC, have 2.2 uf Vishay's on the upper MSB's, plus some styrene's and siemens stacked films underside, the metal round can LM49710's for i/v, fast soft diodes with snubber's and have ordered Shinkoh Tantalum resistors for DATA and WS ( 390R ) and six more for round the i/v op amps. CK resistor will be redundant once I've split pins 2 and 4 for clocking so I didn't need a 120R here.
I toyed with Z Foils for the 2 x 390R's but at £40 delivered it seemed a bit rediculous - I still think about this though after reading peoples feedback on what they do - the specs are eye watering to say the least.
The signal will leave the board at the i'v op amps and go to the valve buffer via silver coax.
I've a plan to suspend the dac board and increase it's mass too and once I've done some testing I'll post up how it looks.
Not sure what it'll do but I'll give it a go anyway.
My real desire is to have 4 matching oiled hardwood cheek pieces made for the two cases. Yeah, aesthetics I know...but don't you just love the look of the CD 94 and the other wood sided machines ?
All in good time - I've got plenty of that thankfully but I will do it.
This one is really about neatness, shorter raw wiring, better soldering and joints, nicer components and no repairs to tracks.
MK1 Alpha has been my education, frustration and joy in equal measure.
Mk2 will be a statement of my new found patience.
It'll also have my Alpha cased external PS connected...now that is exciting.
I know it works but I've not connected it yet - and can't imagine what it'll do to the sound.
What about you ?
Did you do anything new or are you just enjoying at the moment - it's been a while since we all communicated our mutual madness
Hope all is well
Andrew
Andrew
Sounds like a great plan. I think you will end up with both a great sound and a great look.
I have been caught up improving the digital source upstream of the DAC. On the CMP2 thread we have been tearing winxp to its skeleton to reduce jitter. Keep getting a better signal to feed the tda1541a and it just keeps sounding better.
Post pics as it takes shape.
Walter
Sounds like a great plan. I think you will end up with both a great sound and a great look.
I have been caught up improving the digital source upstream of the DAC. On the CMP2 thread we have been tearing winxp to its skeleton to reduce jitter. Keep getting a better signal to feed the tda1541a and it just keeps sounding better.
Post pics as it takes shape.
Walter
Wow - that's where you've been !
I'm not entirely sure what it all means but it sounds like an advance on CD anyway !! Sorry if that's an insult😀
Definitely like to see pics.
Most of my bits are here now so it'll be pics time for me too soon.
I'm still laboring over how to get good clean DC into the main player properly.
Emphasis on ' properly ' in terms of implementation - only want to do it once.
I can do it but I keep changing ideas from reading too much.
You now how it is.
End of the month and I'll be pressing ' play '
Let's see what your doing soon please
Best
Andrew
I'm not entirely sure what it all means but it sounds like an advance on CD anyway !! Sorry if that's an insult😀
Definitely like to see pics.
Most of my bits are here now so it'll be pics time for me too soon.
I'm still laboring over how to get good clean DC into the main player properly.
Emphasis on ' properly ' in terms of implementation - only want to do it once.
I can do it but I keep changing ideas from reading too much.
You now how it is.
End of the month and I'll be pressing ' play '
Let's see what your doing soon please
Best
Andrew
Hi Simon
Just wondering if you did this mod yet, if it fixed your problem and has it cleaned it up at all ?
Andrew
Embarrassingly I've been so lazy and preoccupied with other things I've just listened to a CD52 I've been modifying instead of sorting it out. I'm getting the CD52 sold now so will get onto the coax "upgrade" very soon. One thing I've been doing is taking my 2nd Electrical Installation exam - a career move that is nicely complimentary with the hi-fi hobby. I just wanna install a dedicated ring for the hi-fi with 6mm^2 cooker cable 😀
Is there any room left for 6 mm wire inside your machine ? 😀
If I've got this right - you'll be a fully fledged Electrician ?
My neighbour is a self employed Electrician and he has a very nice new Mercedes.😉
Seems like a good career path to me !!
Best of luck with your exams Simon.
Hey, just thought.... you'll get big discounts at RS too !!
If I've got this right - you'll be a fully fledged Electrician ?
My neighbour is a self employed Electrician and he has a very nice new Mercedes.😉
Seems like a good career path to me !!
Best of luck with your exams Simon.
Hey, just thought.... you'll get big discounts at RS too !!
Thanks Andrew, I do hope it can make me a good living and it's something I'm really interested in. The goal is to become an electrician, just a few hoops to jump through / education first. 2nd exam went well, just 2 more on this course.
There's room for wire... when I've removed the old wire!
There's room for wire... when I've removed the old wire!
I finally put my mini coax in this evening, for all 4 re-clocked circuits: pins 2 & 4 on the DAC, decoder and digital filter. It was a bit of a pain to do being honest, but it is working. I don't yet know if it's fixed the cutting out problem but it's played the first CD almost all the way through and has yet to stutter or cut out once.
Obligatory pics attached.
Obligatory pics attached.
Attachments
...and after posting the player cut out on track 13/14. Starting it again, it stops on any track. It seems to be that perhaps something doesn't like to be warm.
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