Cayin CDT-17A

teiki arii · Beitrag von **teiki arii** » Mi 26. Okt 2005, 22:19

Erzkanzler hat geschrieben:
teiki arii hat geschrieben:Do you allow me to post it on the french thread?
You can use the pictures as you like.
EDIT: Be careful, the bridges are ONLY on the last OPA. PIN 1 + 3, 5 + 7.
Regards
Martin

yes on the "desymetrisation" one,
thank you very much indeed,
teiki...

Tom_H · Beitrag von **Tom_H** » Mi 26. Okt 2005, 22:19

Except the bridges, that is similar to that what I did with my Music Van.
The improvement is a much deeper soundstage and less harshness.

As soon as I finished my investigations, I will post at the MV modding thread.

waterl00 · Beitrag von **waterl00** » Mi 26. Okt 2005, 22:25

Hi Teiki,

I have seen that you have the headphone Amp HA-1A from Cayin.

In this thread I asked wether someone has some experience with this amp, maybe you could answer it there.

Thanks and regards
Jost

teiki arii · Beitrag von **teiki arii** » Mi 26. Okt 2005, 22:32

waterl00 hat geschrieben:Hi Teiki,
I have seen that you have the headphone Amp HA-1A from Cayin.
In this thread I asked wether someone has some experience with this amp, maybe you could answer it there.
Thanks and regards
Jost

Sorry, I did not see it.
I think I have already said something, haven't I? I will do it for sure.

PS: what a shame not to speak german for german community, but I can speak russian...

French post of Erzkanzler realisation:
http://www.homecinema-fr.com/forum/view ... #169180463

Don't forget Erzkanzler, try OPA627BP, OPA627AP, AD843 and let us know...

Amerigo · Beitrag von **Amerigo** » Do 27. Okt 2005, 08:24

Teiki

English is good. Most of us speak it but as long as nobody starts speaking english, nobody will chime in.

Le français, c'est pire

Cheers

Amerigo

PS: Can you guys tell me something? If I take a standard CD-T17a (mine) and compare it to your beefed up versions - how much would be the difference? Can you tell in percentage, or in tonal qualities? What do you think I just have to do? OPA change? Can you say how much difference it makes?

Erzkanzler · Beitrag von **Erzkanzler** » Do 27. Okt 2005, 08:39

Hello,

looking at the sketch of teiki in the french forum, I'm wondering what the hell is the idea of Zhou. That makes no sense.

I'll work on this stage today and give you the feedback.
Normally, as this is a buffer stage (non-inverting), you have to shorten the pins 3 and 6, otherwise as a inverting stage no bridge is necessary.

If you take a look to the 2604 double operational amplifier, that makes sense. I guess Zhou made a small mistake.

Regards
Martin

teiki arii · Beitrag von **teiki arii** » Do 27. Okt 2005, 08:41

Erzkanzler hat geschrieben:Hello,
looking at the sketch of teiki in the french forum, I'm wondering what the hell is the idea of Zhou. That makes no sense.
I'll work on this stage today and give you the feedback.
Normally, as this is a buffer stage (non-inverting), you have to shorten the pins 3 and 6, otherwise as a inverting stage no bridge is necessary.
If you take a look to the 2604 double operational amplifier, that makes sense. I guess Zhou made a small mistake.
Regards
Martin

Let us wait...

ManfredK2 · Beitrag von **ManfredK2** » Do 27. Okt 2005, 08:56

ER bietet seine Player derzeit im HIFI-Forum per PN an

teiki arii · Beitrag von **teiki arii** » Do 27. Okt 2005, 10:05

Be careful, the bridges are ONLY on the last OPA. PIN 1 + 3, 5 + 7.

Erzkanzler · Beitrag von **Erzkanzler** » Do 27. Okt 2005, 10:14

Teiki,

it's stupid. Seems that Zhou wanted to fool us.

I've just removed the bridges and it works perfect.

Regards
Martin

teiki arii · Beitrag von **teiki arii** » Do 27. Okt 2005, 10:16

So, What is to be done exactly?

Bridge between 3 and 6...

Tom_H · Beitrag von **Tom_H** » Do 27. Okt 2005, 10:22

I am using no bridges in my Music Van and it works perfect.........

I will give it a try with bridges, but do not expect any advantage.

Erzkanzler · Beitrag von **Erzkanzler** » Do 27. Okt 2005, 10:32

Hello Teiki,

no bridges, only remove the 4 OPA604/or whatever you use.

The output level will decrease, let's say roundabout -3dB.
But it works perfect.

Pictures later, my wife is on the road with the digital.

Best regards
Martin

BTW, the bridges just do nothing - in bad or good - just nothing.

EDIT: My PCB is revision 2004-6-16

Erzkanzler · Beitrag von **Erzkanzler** » Do 27. Okt 2005, 10:35

@ Tom,

Du brauchst das mit den Brücken nicht zu probieren, entweder es funktioniert ohne (und das klappt ja beim MV) oder Du bekommst überhaupt kein Signal.

Grüße
Martin

teiki arii · Beitrag von **teiki arii** » Do 27. Okt 2005, 10:53

Erzkanzler hat geschrieben:Hello Teiki,
no bridges, only remove the 4 OPA604/or whatever you use.
The output level will decrease, let's say roundabout -3dB.
But it works perfect.
Pictures later, my wife is on the road with the digital.
Best regards
Martin
BTW, the bridges just do nothing - in bad or good - just nothing.
EDIT: My PCB is revision 2004-6-16

YES!
I have just tried with 2xOPA627BP -best than OPA627AP Martin- and 2xAD843JNZ and it works perfectly!!!!
But is it dangerous?
Best regards, a big improvement indeed...

So, just remove AOP#1 and AOP#2 and keep only the AOP#3 for each chanel for your Cayin CDT-17A RCA exclusive:
[img:642:668]http://www.membres.lycos.fr/sst00940/numeros.JPG[/img]

Erzkanzler · Beitrag von **Erzkanzler** » Do 27. Okt 2005, 11:36

Hello Teiki,

unfortunately my french is as bad as my chinese

Have you discussed in the french forum the possibility of changing the I/V-circuit IC NE5532? This seems to me the biggest bottleneck in the whole layout.

Best regards
Martin

teiki arii · Beitrag von **teiki arii** » Do 27. Okt 2005, 12:08

Erzkanzler hat geschrieben:Hello Teiki,
unfortunately my french is as bad as my chinese
Have you discussed in the french forum the possibility of changing the I/V-circuit IC NE5532? This seems to me the biggest bottleneck in the whole layout.
Best regards
Martin

Of course, we did but we are afraid of changing it. I always update the first page of the topic when something interesting...

Someone of us took off the red heatsink and NE5532 has been replaced -by Spark/Cayin- by AD827...

One day, I thing I'll try AD826 or something else since I have tried AD847 -exactly same as AD827 but single AOP, not dual- on Filter and desymetriastion stage without benefit...Less good than OPA627, OPA134, AD843...

Tom_H · Beitrag von **Tom_H** » Do 27. Okt 2005, 14:47

Erzkanzler hat geschrieben:unfortunately my french is as bad as my chinese

oh, that good.........I am surprised.........

sorry for the ot but I couln't resist.........

Amerigo · Beitrag von **Amerigo** » Do 27. Okt 2005, 14:59

Est-ce que vous avez vu ma question la-haut?

Merci

Amerigo

teiki arii · Beitrag von **teiki arii** » Do 27. Okt 2005, 15:32

Amerigo hat geschrieben:Can you guys tell me something? If I take a standard CD-T17a (mine) and compare it to your beefed up versions - how much would be the difference? Can you tell in percentage, or in tonal qualities? What do you think I just have to do? OPA change? Can you say how much difference it makes?

When you change AOP, it is like changing CDP! It's quite different from an AOP to another one. But I have tried some of them and the ones I have kept, are:
- OPA627BP
- AD843JNZ
- OPA134AP
Now, if you use only RCA outlet, just put 2 AOP instead of 6 AOP -according to what Martin told us- and besides just two tubes out of four near the output RCA...
best regards.

So, just remove AOP#1 and AOP#2 and keep only the AOP#3 for each chanel of your Cayin CDT-17A RCA exclusive:
[img:642:668]http://www.membres.lycos.fr/sst00940/numeros.JPG[/img][/quote]