[antness]

I took apart an Arcam CD23 to see the components. I took a quick look, and am not going to completely dissect it to figure out any of the circuit cause i'm taking it back to the store on tuesday

Transformers: There are two, one is a toroidal mounted to the chassis, and the other one, pretty sure it is a transformer, is about the size of the Talema but is encased in a box of metal so I can't get a look at it.

Capacitors: Almost all Rubycon throughout, there is 1 cerafine about 220uF and three or four light brown Elnas (not sure what kind these are).

Opamps: OPA2134, OP275, LM6182. The OPA2134 are right behind the analog output jacks.

I can't mod this unit as i'm returning it, but it looks like it might be worthwhile to consider. The OPA2134 could certainly be replaced with a better chip, and there is lots of room in between capacitors to swap them out for Black Gates.

 

[aeberbach]

I believe those light brown Elnas are SILMIC grade, supposedly better than Cerafine. I recall seeing AD825 when I opened mine up. Maybe production changed?

 

[andrzejpw]

where did you see AD825s? In place of the 2134s?

 

[puppyslugg]

I dunno, for the price of nearly $2200, I would have expected better chips.

Or is it you need to move up to the 3-5k range, you get better chips?

 

[antness]

I found that odd too...$2199, and you can't put in a $6 chip over a $2 chip?

 

[puppyslugg]

antness,

Could you tell if the chips were biased class A?

 

[wasifazim]

Quote:

Originally posted by antness Capacitors: Almost all Rubycon throughout, there is 1 cerafine about 220uF and three or four light brown Elnas (not sure what kind these are).

If they're Elna Silmic, that should be clearly written on the side in gold lettering, otherwise they're lower grade. Can't be Cerafine; those are red.

- Wasif.

 

[halcyon]

If you want to take the guessing out of your cap upgrade, then buy the August - December issues of Electronics World (UK) magazine where several different types of capacitors are measured for NOT Only their total harmonic distortion, but also for their intermodulation components at various bias voltages. Or just buy the Dec issue and wait until the author publishes a CD-ROM full of cap measurement data (he's measured hundreds of caps).

Changing caps blindly to the latest audiophile craze (TRT, Auricap, Black Gate, Jensen, etc) might not always work, unless you know how each cap will behave in the given electronic application.

regards,
Halcyon

PS Arcam FMJ CD23(t) is already at the very top of it's heap according to the best reviews and measurements I've read (Stereoplay/GER, Audio/Ger, Hifi/FIN). Only bested by some units by Linn, Burmester and Accuphase costing c. 10 x more. I wish I had it for a source myself. But YMMV, of course.

 

[aeberbach]

I think the 825s were at the output of the DAC, they were on the board labeled "Alpha 9 DAC" under the metal panel. Of course this is all a couple of years ago now so that may just be the way they used to do it, or I might be remembering incorrectly.

That's a good tip halcyon. I haven't googled yet but do you have a URL for them?

 

[ServinginEcuador]

Antness,

Are the op amps soldered in, or are they mounted in IC sockets?? You will probably void the warranty if yo uhave to pull the PCB out and modify it to facilitate socket installation.

I ask as I had to take my CDP into the shop to have some sockets put in to it so I could easily swap out chips. Also, make sure you check the voltage into those op amps as I dropped in some really good OPA627 chips from Burr Brown, and they really sucked. These things are voltage hogs and need more voltage than my op amps had, and they would get unstable and sound horrible every time there was a sudden dynamic passge.

I have really enjoyed the LC Audio modules that come with decoupling caps and an AD825 built-in. I am currently using the AD843s, but don't like them as much. The only chips I haven't tried are the AD8610s I've heard so much about.

 

[antness]

All of the opamps are soic, i think, except the LM6182 which I believe are socketed. I honestly don't remember, I'd have to take it apart again to check

 

[eric343]

Ouch, SOIC... Damn. The CD72 is all-DIP; much much easier to mod. (I soldered some DIP sockets into mine and swapped the TL072 for an OPA134; I've been meaning to replace it for an AD825 when I get "around to it")

And yeah, the opamps run off quite low voltage - when I measured it, it was 5 or 9 volts rail to rail.

I wonder if it'd be possible to do a SOIC->DIPsocket adapter...

 

[ServinginEcuador]

Quote:

Originally posted by eric343 Ouch, SOIC... Damn. The CD72 is all-DIP; much much easier to mod. (I soldered some DIP sockets into mine and swapped the TL072 for an OPA134; I've been meaning to replace it for an AD825 when I get "around to it") And yeah, the opamps run off quite low voltage - when I measured it, it was 5 or 9 volts rail to rail. I wonder if it'd be possible to do a SOIC->DIPsocket adapter...

Try emailing or PMing Puppyslug, I think he PM'd me a site with all kinds of op amp adaptors, so try contacting him. Unless he's reading this - TONY!! Hey Tony, you listening???

 

[puppyslugg]

Quote:

I wonder if it'd be possible to do a SOIC->DIPsocket adapter...

This sounds like a project for morsel.

Speaking of morsel, where has she been? Last I heard, she was going to be away for the month of Oct..... well, it's Nov. now.

morsel?

------------------------------------------------------------------------------------

ServinginEcuador:

The adaptors I recommended to you were BrownDog adaptors. They were designed by morsel for us diyer's. When you need to use one, you can thank morsel.

 

[ServinginEcuador]

Quote:

Originally posted by puppyslugg This sounds like a project for morsel. Speaking of morsel, where has she been? Last I heard, she was going to be away for the month of Oct..... well, it's Nov. now. morsel? ServinginEcuador: The adaptors I recommended to you were BrownDog adaptors. They were designed by morsel for us diyer's. When you need to use one, you can thank morsel.

Thanks a lot for the help Tony!!! Man, that was like wierd how I put that post in and BAM, you were there and replied like that. Cool!! I will thank morsel for making them available, but you also for making them known!!!