Ooops! Just noticed a typo on my earlier post. Of course the regs are 7909 and 7809 (9V) on the servo, not the 7906/7805 I wrote.
Yes, it's best to bet the player in for a while before doing anything else.
I have a Rotel RCD965BX which is essentially the same as the Arcam right up to the DAC which is bitstream in the Rotel. So I have no experience with the mods to the TDA1541 DAC.
Joe
Just an observation - the E Bay prices of Arcam Alpha's is going through the roof and I can't really understand why.
It can't possibly be because of this thread.......can it ?
...c'mon own up...who was the 38th bidder that put £110.00 on last night ?
Idiot !!
btw - I was NOT the 37th bidder @ £108 - another idiot
One more thing......Anyone tempted by the guy selling Single Crown TDA chips for £ 62.00 ?
I've been speaking to him and he tells me they are all pulled from boards ( they look like it too when observing the pins ) and are all tested to be open circuit on all pins.
The printing looks right too....I think
I'm no expert as you know but I've looked at literally hundreds this last few days just observing the different variations in font, ink type, positioning and colour density plus the explanations ( some on this site ) of where and how they were marked up and the reasons behind it.
Some of the fakes are laughable but some are actually quite good too - which is worrying.
I'm sorely tempted to have a shot at one of these as I have no problem getting my money back in these moments of madness.
The guys feedback is good - there's no mention of fakes, his Dual Crown sales have all had positive feedback comments left for him and he offers full refunds irrespective of the reasons.
His Dual Crown variants have been going for over £ 200 so they are off menu.
Can anyone tell me if the step up from standard 1541 A to Single Crown is noticeable..?
It can't possibly be because of this thread.......can it ?
...c'mon own up...who was the 38th bidder that put £110.00 on last night ?
Idiot !!
btw - I was NOT the 37th bidder @ £108 - another idiot
One more thing......Anyone tempted by the guy selling Single Crown TDA chips for £ 62.00 ?
I've been speaking to him and he tells me they are all pulled from boards ( they look like it too when observing the pins ) and are all tested to be open circuit on all pins.
The printing looks right too....I think
I'm no expert as you know but I've looked at literally hundreds this last few days just observing the different variations in font, ink type, positioning and colour density plus the explanations ( some on this site ) of where and how they were marked up and the reasons behind it.
Some of the fakes are laughable but some are actually quite good too - which is worrying.
I'm sorely tempted to have a shot at one of these as I have no problem getting my money back in these moments of madness.
The guys feedback is good - there's no mention of fakes, his Dual Crown sales have all had positive feedback comments left for him and he offers full refunds irrespective of the reasons.
His Dual Crown variants have been going for over £ 200 so they are off menu.
Can anyone tell me if the step up from standard 1541 A to Single Crown is noticeable..?
Marantz, Phillips and Arcam CD players are escalating in price on ebay here in Australia too. There is a Marantz CD-74 going on ebay here for A$350.00 (about £226.00)
The vendors are touting these, and anything else with a TDA15141 DAC, as "audiophile" and "high end" players. For example this is the item description of a Marantz CD40 in a current auction "Marantz high-end cd player cd-40 Made in beligum." The latest bid is A$100.00 but there are still two days to go. This is a plastic cased job, but it has a 1541, so it must be high-end?
Or the "NEC HI END CD PLAYER / superb sony transport - with PHILIPS tda1541a DAC" currently at A$177.00
Perhaps the popularity and consequent prices of these players does have something to do with the the forums on DIYAudio – or perhaps just the vendors seeing an opportunity to make a quick dollar from "audiophiles."
I am interested in replacing the bitstream DAC in my Rotel with a TDA1541 and I have been checking the 1541s for sale on ebay. Its a bit of minefield by the look of it. I found this one from China, which looks very nice and clean and crisply labelled written.
To be realistic I guess it has to depend on the individual chips. As far as I'm aware the crowns are just normal chips where the tolerances are below (above?) a particular level. So you could be replacing a chip at the top of the non-crown tolerance range with one at the lower end of the crown tolerance range.
Regards
Pete
Quite, the step "up" may be a step sideways depending what you had before. I know it's hearsay and not facts but I was told the manufacturing location of the chips was also very important and a non-crown from Taiwan was better than from elsewhere. I bought such a chip for about £10 and did hear some improvements. I probably wouldn't spend £62 getting small gains, unless money was no object or I'd exhausted more productive avenues. It should be possible to buy a single-crown player for £200 or so, making that chip look a tad pricey. I think sellers are getting very wise to the money-making potential of the old classics.
The plastic players are not high-end but all 1541 and 1541A players have a distinctive, chunky sound. Oh and my old Philips CD650, when suitably modified, had a certain seductive quality I'm not the Arcam has ever matched (though the Arcam has surpassed it with the objective sound quality observations). It's hard to say if it's due to plastic or due to the boards, CDM2 mech, ceramic caps or something else.
The plastic players are not high-end but all 1541 and 1541A players have a distinctive, chunky sound. Oh and my old Philips CD650, when suitably modified, had a certain seductive quality I'm not the Arcam has ever matched (though the Arcam has surpassed it with the objective sound quality observations). It's hard to say if it's due to plastic or due to the boards, CDM2 mech, ceramic caps or something else.
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Perhaps it's a factor! I don't know. As you saw I wrote a little thing on a site my friend and I have about it: DIY Media Home Upgrading an original Arcam Alpha DIY Media Home
What puzzles me is why searching for Arcam Alpha modifications pulls up loads about the ugly-duckling Alpha 5 and not the original Alpha, which looks so much nicer and goes for a similar price.
The hype that surrounds the TDA1541 is obvious even on this site.
Some people are gullible and belive that was some kind of conspiration to stop manufacturing those DAC's, to impose a dreaded "OS" and delta-sigma DAC's and therfore, those old DAC's are something to desire...
Some people are gullible and belive that was some kind of conspiration to stop manufacturing those DAC's, to impose a dreaded "OS" and delta-sigma DAC's and therfore, those old DAC's are something to desire...
Indeed there is much hype in some circles, and I'm not immune to it. I think there's a quality I like in the sound, a chunky solidity that eludes many CD players. I know enough, however, to realise less famous DAC chips that are cheaper can be the heart of players or standalone DACs that can largely outperform a more modest or old TDA-based player or DAC. I've not lived with enough chips to know if I can love another like the 1541 but I thought what I heard from a modified CD17KI had some of the positive traits, as well as a stronger, deeper bass and more open top end. It's difficult to pin down how much is the DAC chip itself and how much is the power supplies, transport/mech, servo, filter, output stage and so on.
I think that a good servo, power supply and output stage makes a lot of difference in any player.
So do I, and very much so. The other point I was trying to make was that some players have a better this or a better that and contribute in ways which could falsely be attributed to the DAC chip alone. CD94 is a classic not just because of TDA1541 but because of a beasty mech and servo too, plus heavyweight supplies.
It's too quiet on here - time to make some additions.
Bought a PLUS model a month or so ago and have just started changing things on the DAC board.
My previous effort whilst sounding lovely is a bit of a mess in so many ways.
Repaired tracks that I'd burnt the sh.. out of, wires all over the place without much thought and parts shoved in from the spares bucket with a ' that'll do mentality '
I now have my external power supply ready and it's so tidy inside that I thought I'd have one last go and apply the same tidy mind approach. Maybe spend a little extra on the right parts this time and see what happens.
So far so good, nice little gains - as to be expected with just DAC tweaks.
It's so ' shut in ' though next to my nice one and I'm enjoying hearing the effects of my previous work - the original really is completely night and day better at the moment - and so it should.
It all started to get interesting a couple of days ago whilst doing the new dac and decided to put in another standard old dac board so I had music.
Pressed play and the disc was just spinning fast.
On closer inspection the layout of a 92 Plus dac board is totally different in layout - the 10 pin signal plug for example is wired in a completely different way. There are additional components like BC547's and even an extra cap adjacent to one of the LM337's - I have two other standard machines from 89 so I can easily compare.
So, the Alpha Plus is not just a ' Plus ' due to a pair of Black Gates on the output - I found this quite strange tbh - why have Arcam done this I wonder.
The main board has fewer caps on it too but I suspect that'll be cost cutting.
I'll be filling the empty slots on this board when I get to it.
Taking my time on this one because I can... so I won't be frenetically posting
things every week.
Hope to produce something a bit special by the end of it all - but super regs are not on the list till at least February......
I've missed doing this
Bought a PLUS model a month or so ago and have just started changing things on the DAC board.
My previous effort whilst sounding lovely is a bit of a mess in so many ways.
Repaired tracks that I'd burnt the sh.. out of, wires all over the place without much thought and parts shoved in from the spares bucket with a ' that'll do mentality '
I now have my external power supply ready and it's so tidy inside that I thought I'd have one last go and apply the same tidy mind approach. Maybe spend a little extra on the right parts this time and see what happens.
So far so good, nice little gains - as to be expected with just DAC tweaks.
It's so ' shut in ' though next to my nice one and I'm enjoying hearing the effects of my previous work - the original really is completely night and day better at the moment - and so it should.
It all started to get interesting a couple of days ago whilst doing the new dac and decided to put in another standard old dac board so I had music.
Pressed play and the disc was just spinning fast.
On closer inspection the layout of a 92 Plus dac board is totally different in layout - the 10 pin signal plug for example is wired in a completely different way. There are additional components like BC547's and even an extra cap adjacent to one of the LM337's - I have two other standard machines from 89 so I can easily compare.
So, the Alpha Plus is not just a ' Plus ' due to a pair of Black Gates on the output - I found this quite strange tbh - why have Arcam done this I wonder.
The main board has fewer caps on it too but I suspect that'll be cost cutting.
I'll be filling the empty slots on this board when I get to it.
Taking my time on this one because I can... so I won't be frenetically posting
things every week.
Hope to produce something a bit special by the end of it all - but super regs are not on the list till at least February......
I've missed doing this
Hi Andrew,
I didn't know there was an Arcam Alpha Plus, or is this the Alpha 5+? I wonder what the extra transistors are doing, could they be muting to replace the relays (cost-saving) or some kind of regulator add-on or capacitance multilier perhaps, or switch-on delay? I dunno.
You're right to take your time and be neat, you'll be more likely to get the end result you want.
I didn't know there was an Arcam Alpha Plus, or is this the Alpha 5+? I wonder what the extra transistors are doing, could they be muting to replace the relays (cost-saving) or some kind of regulator add-on or capacitance multilier perhaps, or switch-on delay? I dunno.
You're right to take your time and be neat, you'll be more likely to get the end result you want.
I ordered some small diameter coax to re-wire my clock lines as I think RF pollution may be causing my stoppages. I think twisted pair is ok for short lines but with all the wire trailing around my player it's asking for trouble to not use shielded coax. I can't remember if I said on here but I swapped my laser and whilst the player behaves differently there's still something thwarting its mission to play a track of music start to end.
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Actually, that's a nice tip Simon - thanks.
I'll do that too when I get to it.
My wiring leaves a lot to be desired - I'd like my clock somewhere nearer to all the receivers so the wiring is shorter....I'll leave that for now !!
Can't remember you mentioning changing the laser but I did think you'd found the problem and fixed it.
Oh dear.
Well, the original offer still stands if your pulling your hair out - don't hesitate.
Finally, yes an Alpha Plus model exists and has a pair of black gates on the output. They were about £50 more than the standard Alpha just before it's replacement range was launched ( Alpha 5 and + )
I just thought it was exactly the same inside with just the caps changed and metal cheek pieces re moulded.
In fact now I've had a close look at all three dac boards that I have they are all slightly different in layout... but this 92 model is VERY different.
I'll post a pic up of it soon so you can see it yourself - weird.
I'll do that too when I get to it.
My wiring leaves a lot to be desired - I'd like my clock somewhere nearer to all the receivers so the wiring is shorter....I'll leave that for now !!
Can't remember you mentioning changing the laser but I did think you'd found the problem and fixed it.
Oh dear.
Well, the original offer still stands if your pulling your hair out - don't hesitate.
Finally, yes an Alpha Plus model exists and has a pair of black gates on the output. They were about £50 more than the standard Alpha just before it's replacement range was launched ( Alpha 5 and + )
I just thought it was exactly the same inside with just the caps changed and metal cheek pieces re moulded.
In fact now I've had a close look at all three dac boards that I have they are all slightly different in layout... but this 92 model is VERY different.
I'll post a pic up of it soon so you can see it yourself - weird.
Yes, there definitely is an Alpha Plus, as I still have one bought new back in the very early 90s. It's kind of the forgotten model in the range as it was only out for a short period before the new Alpha range came out and it was arguably better than what came both before and after.
I'd seen the speculation before that the only difference over and above the regular Alpha was a pair of Black Gates on the output but that's surprised me given the significantly better reviews this unit received in comparison to the stock Alpha at the time.
I should probably dig mine out, get it open and see what scope there is for improvement, especially seeing how easy it is to work on from this thread!
Hello Paulster, welcome to the Alpha mentalists club !
If you do have a go at it and follow from Simon's first post you'll be pleased you did.
Once familiar with it in terms of taking it apart and reading the damn service manual ( I hated reading the f.....g thing 😕 and usually asked Simon ) it becomes a bit of a pleasure to work on and rewards you pretty early on with some simple mods. Step it up a notch or two and it becomes thrilling. Can't think of a better word really...thrilling it is then !!
There's also one or two Eureka moments in this thread from pretty much all of us who have them 😀
Back to the Plus :
I noticed the two transformers are a long way apart on the separate board - eliminates the buzzing if they are touching and maybe interference reduction ?
God knows.
The DAC board is a light green colour and is transparent held up to the light - no use in that then.
Finally the TDA is on it's own 28 pin socket so it can be removed....chip swapping anyone ?
Maybe they were going to fit S1 grade TDA's like the Delta 70-2 or give owners the option to do this later.
C227 cap is also a massive green one ( technical ! ) - or analogue ground cap
It was better than the standard Alpha in stock form apparently and was sold as the upgrade model but right now it sounds awful compared to what I've got right now.
That'll change !!
Still, it's quite fascinating and I've noticed the prices on E Bay are up to and sometimes over £100 - wonder whose buying these things - they'll be lurking here somewhere !
If you do have a go at it and follow from Simon's first post you'll be pleased you did.
Once familiar with it in terms of taking it apart and reading the damn service manual ( I hated reading the f.....g thing 😕 and usually asked Simon ) it becomes a bit of a pleasure to work on and rewards you pretty early on with some simple mods. Step it up a notch or two and it becomes thrilling. Can't think of a better word really...thrilling it is then !!
There's also one or two Eureka moments in this thread from pretty much all of us who have them 😀
Back to the Plus :
I noticed the two transformers are a long way apart on the separate board - eliminates the buzzing if they are touching and maybe interference reduction ?
God knows.
The DAC board is a light green colour and is transparent held up to the light - no use in that then.
Finally the TDA is on it's own 28 pin socket so it can be removed....chip swapping anyone ?
Maybe they were going to fit S1 grade TDA's like the Delta 70-2 or give owners the option to do this later.
C227 cap is also a massive green one ( technical ! ) - or analogue ground cap
It was better than the standard Alpha in stock form apparently and was sold as the upgrade model but right now it sounds awful compared to what I've got right now.
That'll change !!
Still, it's quite fascinating and I've noticed the prices on E Bay are up to and sometimes over £100 - wonder whose buying these things - they'll be lurking here somewhere !
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It's good to hear more about this Plus model. I can't see the socket doing much good, I'd rather de-solder and re-solder it but if you're not comfortable with that it's an easier way to upgrade to single or double crown. The only issue is pins bending as I seem to recall they like doing when coming out of those sockets.
Hi Andrew, Paul, Simon and others,
I always enjoy reading this thread, it's amazing how much you guys have got out of these players. I own both a Alpha and an Alpha +, and it may have been my comments that you referred to, it sounds like what I've said in the past.
Yes, the layout between the two is completely different in the way that most things are in different places, but they are still laid out broadly the same, and the BoM only differs by a couple of capacitors. To me it's more of a revision than a new design. I'm not sure whether the 10 pin IDC headers on mine are wired differently, I'll check that. The service manual I have suggests they should be the same, both; 1) BCLK, 2) DEEM, 3) WCLK, 4) NC, 5) DATA, 6) MUTE, 7) GND, 8) NC, 9) GND or NC, 10) GND, except pin 9 which is only grounded on the +. Both of mine have the same number of BC547s, four of each, two for deemphasis, two to drive the muting relay. There are a pair of FST239 / FST240 as pre regulators on the +.
I'm pretty sure I put the socket in my plus, when I bought it the TDA1541A was soldered directly to the board.
I seem to remember that one of my Alphas (I think it was the +) came with all of the passives for the original output stage still present, with only the opamps and output connectors removed. My other Alpha came with only what the Alpha needs, and it had been made by Philips like this (the original wave soldering was undisturbed). The photos don't show this because I removed the redundant components before this photo was taken.
Not on mine, they're both the same.
It seems like there are quite a few revisions of the Alpha with some significant changes. I'd be interested to see some photos of your new Alpha + Andrew to compare to mine.
Little changes can make a difference in these players, I've got the two Alphas, a Mission PCM2, a Mission PCM7000 and I've heard many other TDA1541A based players, and they're all different.
I always enjoy reading this thread, it's amazing how much you guys have got out of these players. I own both a Alpha and an Alpha +, and it may have been my comments that you referred to, it sounds like what I've said in the past.
Yes, the layout between the two is completely different in the way that most things are in different places, but they are still laid out broadly the same, and the BoM only differs by a couple of capacitors. To me it's more of a revision than a new design. I'm not sure whether the 10 pin IDC headers on mine are wired differently, I'll check that. The service manual I have suggests they should be the same, both; 1) BCLK, 2) DEEM, 3) WCLK, 4) NC, 5) DATA, 6) MUTE, 7) GND, 8) NC, 9) GND or NC, 10) GND, except pin 9 which is only grounded on the +. Both of mine have the same number of BC547s, four of each, two for deemphasis, two to drive the muting relay. There are a pair of FST239 / FST240 as pre regulators on the +.
I'm pretty sure I put the socket in my plus, when I bought it the TDA1541A was soldered directly to the board.
I seem to remember that one of my Alphas (I think it was the +) came with all of the passives for the original output stage still present, with only the opamps and output connectors removed. My other Alpha came with only what the Alpha needs, and it had been made by Philips like this (the original wave soldering was undisturbed). The photos don't show this because I removed the redundant components before this photo was taken.
Not on mine, they're both the same.
It seems like there are quite a few revisions of the Alpha with some significant changes. I'd be interested to see some photos of your new Alpha + Andrew to compare to mine.
Little changes can make a difference in these players, I've got the two Alphas, a Mission PCM2, a Mission PCM7000 and I've heard many other TDA1541A based players, and they're all different.
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