SimontY said:
LOL. If you read my posts on the cd63 thread, you may find most are off topic!
I'll be having another go at the little Marantz later on today and will let you know the progress. I'll add an extra tx and isolate the supply rails to the dac and SAA7220.
The transport in this thing is a cdm2 btw. The whole mech floats on its own rubber suspension, totally decoupled from the rest of the (**** plastic) chassis.
All the chips seem to be philps Phil.
Lee.
Thomo said:
Hi Lee
i havn't done anything to it at all........!!!
absolutely standard.
I must admitt, in standard form, it has a very analogue sound too it.
Nowhere near the detail of my modded cd67, but better than a standard cd67.
From what "philpoole" and others have said...
Clean up the Saa7220 filter psu and clock.
As for opamps? Look for Nelson Pass's D1 discrete output.
It was going to try it on this player, just never got around to it.
allan
General question for anyone.
The Rotel's used BG cap's standard.
How long does a BG electrolytic last?
Now we are getting off-topic!;¬)
I once read that a BG lasts much longer than a standard elco. The writer said around half again as many years, so by my estimation that makes ~15 years. I am not sure about this, it may just have been marketing blurb. I think it depends on how close to the maximum voltage you run them also.
Saying this, BC Aerovox say their caps will sit on a shelf for well over ten years with no detrimental effects. I have two very old, 6800uF 100v Aerovox's which I used for a while on my Gainclone and they were fantastic. They're a similar size to Brents Silmics btw Simon!
If you are talking about the Rotel, I think it has a filter built into the dac and this may limit the performance along with the power supply.
Lee.
I once read that a BG lasts much longer than a standard elco. The writer said around half again as many years, so by my estimation that makes ~15 years. I am not sure about this, it may just have been marketing blurb. I think it depends on how close to the maximum voltage you run them also.
Saying this, BC Aerovox say their caps will sit on a shelf for well over ten years with no detrimental effects. I have two very old, 6800uF 100v Aerovox's which I used for a while on my Gainclone and they were fantastic. They're a similar size to Brents Silmics btw Simon!
If you are talking about the Rotel, I think it has a filter built into the dac and this may limit the performance along with the power supply.
Lee.
Hi Thomo,
Sorry I was being off thread - I thought Simon's was a CDM4.
CDM2 - blimey! How old is this player?
Have you got any photos of the CDM2?
So, I doubt the little board is a converter then if its all Philips chips. The plot thickens. Can you get a side shot of it? Maybe we'll be able to spot the odd component?
Cheers,
Phil
Sorry I was being off thread - I thought Simon's was a CDM4.
CDM2 - blimey! How old is this player?
Have you got any photos of the CDM2?
So, I doubt the little board is a converter then if its all Philips chips. The plot thickens. Can you get a side shot of it? Maybe we'll be able to spot the odd component?
Cheers,
Phil
Hi Phil. It's OLD. lol. Doesn't even have a remote sensor!
Component side:
Trace Side/Pinout
Both transistors are labeled c548b.
Pin 7 of 7220 is subcode data?
Lee.
Component side:
An externally hosted image should be here but it was not working when we last tested it.
Trace Side/Pinout
An externally hosted image should be here but it was not working when we last tested it.
Both transistors are labeled c548b.
Pin 7 of 7220 is subcode data?
Lee.
I'm sober at the moment, so its tricky, but, I think the little board is an AND gate.
I think.
I take it the black wire is one of pin 33 and pin 38, and the other is just a through hole?
I reckon, although I don't know what a mab8441 is (is it a microcontroller?) that one pin is the subcode data, and the other is an enable line for the subcode data.
Maybe it was an irreversible error in some software in ROM, and this is a cheap workaround (a handful of resistors and transistors probably is cheaper than a quad AND gate IC - especially back then)?
That's my best guess so far, I've got a rough sketch of the circuit, but I'm sort of guessing the pinout for the transistors.
Does this have a digital output? And (if its like my CD624) does it have a digital output enable button? Maybe this is the disable circuit?
With the SAA7220, I know that if the subcode clock (and/or data) is left constant at a level, then it is disabled. And subcode stuff is only used after the digital filter for SPDIF (It doesn't do anything for I2S) as far as I know.
However, I may well have completely the wrong end of the stick.
Cheers,
Phil
I think.
I take it the black wire is one of pin 33 and pin 38, and the other is just a through hole?
I reckon, although I don't know what a mab8441 is (is it a microcontroller?) that one pin is the subcode data, and the other is an enable line for the subcode data.
Maybe it was an irreversible error in some software in ROM, and this is a cheap workaround (a handful of resistors and transistors probably is cheaper than a quad AND gate IC - especially back then)?
That's my best guess so far, I've got a rough sketch of the circuit, but I'm sort of guessing the pinout for the transistors.
Does this have a digital output? And (if its like my CD624) does it have a digital output enable button? Maybe this is the disable circuit?
With the SAA7220, I know that if the subcode clock (and/or data) is left constant at a level, then it is disabled. And subcode stuff is only used after the digital filter for SPDIF (It doesn't do anything for I2S) as far as I know.
However, I may well have completely the wrong end of the stick.
Cheers,
Phil
philpoole said:
Nope, sorry. The leg on the left centre connects to these pins
Anyway, I've fitted a couple of extras now and the results have been very good.
I've fitted an extra tx (2x15vac 3.2va), 2 x Schottky bridges, 4 x 560uF 50v Panasonic FC's.
One winding supplies 560uF FC - 7805 - 100uF Black Gate = 5v to SAA7220.
The other Supplies +5v Audiocom Invisus - TDA1541 +5v.
This little player just keeps on suprising me, it's now within a whisker of my CD67. I admit it's not quite as clean, top and bottom are a little ragged compared. But with one 7915 reg feeding both the dac and the opamps that's not surprising. Detail is very nearly as good, just lacking separation.
I'll add another tx to supply +/-15v to the opamps when I get chance, and beef up the caps to more suitable BG's.
Cheers for all your help guys.
Lee.
An externally hosted image should be here but it was not working when we last tested it.
New PicThomo
Now it's starting to look like a marantz
I found a s/h cd273 today, just not full width like the cd65 (not mk2).
same pcb thought (as the cd65 mk1 as i have).
The saa7220 seems to generate a lot of noise, so
separate psu's for saa7220 and also for the dac.
look at the eathing between the digital components also.
allan
Now it's starting to look like a marantz
I found a s/h cd273 today, just not full width like the cd65 (not mk2).
same pcb thought (as the cd65 mk1 as i have).
The saa7220 seems to generate a lot of noise, so
separate psu's for saa7220 and also for the dac.
look at the eathing between the digital components also.
allan
philpoole said:
The '63KI was modded quite a lot:
http://myweb.tiscali.co.uk/leesaudio/Thomo Mod List.htm
I removed most of the mods though, and put them back on the CD67 as the CD67 was far superior, due to the fact that the servo also gets clocked when you reclock the dac. The cd67 is modded to around the same level as the list above.
This cd273 is defo better than the cd63KI was with all those mods. Just lagging a bit behind the cd67. I'm quite intrigued because I think it'll sound better than my cd67 when re-clocked and flip-flopped etc.
I don't think that it would beat Simon's or Brent's player, even fully modded though (They've added loads of high-quality regs). There are not that many rails you can separate. You only have +/-15v to the opamps, +5v to SAA7220, +/-5v to the dac and -15v to the dac. The cd63's have loads more mods you can apply, each one raising the performance a little bit more.
With the cd63/67 I reached a point where the cost/performance factor became a problem. I have reached the limit of achievable performance without adding lots of expensive regs.
Rambling over
Lee.
That is true about the number of power rails to seperate being fewer on the 273. However, you can still seperate it out, and the DAC does have two grounds for analogue and digital (although which power rail is digital or analogue or mixed is recorded as legend or myth) which can be kept seperate.
With my CD63, I reached the limit of achievable performance without adding catastrophic failure, and just exceeded it.
Oops.
Nevermind.
With my CD63, I reached the limit of achievable performance without adding catastrophic failure, and just exceeded it.
Oops.
Nevermind.
I too have done that before Phil
I have another question now, if you don't mind.
I am trying to build a -15v regulator for the dac, but I keep getting -18.6v output. I'm really confused, especially because I've built tons of them before with no problems. The supply voltage (-25v) is from a separate winding on a new tx with its own rectifier. I have tried using LM7915 and LM337 regulators and get the same voltage both times.
Could it be to do with the grounding inside the player. Both the positive 5v regs are perfect.
Lee.
I have another question now, if you don't mind.
I am trying to build a -15v regulator for the dac, but I keep getting -18.6v output. I'm really confused, especially because I've built tons of them before with no problems. The supply voltage (-25v) is from a separate winding on a new tx with its own rectifier. I have tried using LM7915 and LM337 regulators and get the same voltage both times.
Could it be to do with the grounding inside the player. Both the positive 5v regs are perfect.
Lee.
Right, I think I've solved my reg problem.
I removed the wrong resistor from the 5v line
I have now lost said resistor and really need to know the value. I've attached a pic, so is the nice fellow who also has one of these players could kindly tell me its value, it would be very much appreciated.
It goes from the 5v input to ground, any ideas as to its purpose?
Cheers,
Lee.
I removed the wrong resistor from the 5v line
I have now lost said resistor and really need to know the value. I've attached a pic, so is the nice fellow who also has one of these players could kindly tell me its value, it would be very much appreciated.
It goes from the 5v input to ground, any ideas as to its purpose?
Cheers,
Lee.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.