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Recapping of Nytech CPA 602

you need to be careful about upsetting the trademark holders and heed audio in particular. I don't think you are in the same market at present, but the quality of your stuff could easily end up with going into some sort of low level production. I would guess that your amplifiers would be in a small area of a niche area, but you never know.

The amplifier is in effect a Nytech clone with improvements. There have been other companies that have done well using a standard circuit with improvements. And I don't mean our friend from Chesterfield.

You need a name for the amp that works. Newtech being a poor example. Perhaps Neutech, it looks better. (That ends my knowledge of german - excepting Ein grosse bier bitte!) You could risk "your name" - a nytech clone. At least you are being honest.

Other successes have been quad clones, such as Netaudio and Quad spot /Dada electronics in the netherlands.

In any case good luck.

Mike

PS You've acquired the name nero for the power supply. Perhaps "Nerotech - courtesy of Nytech". That does the german input with a british "tip of the hat" to the originator of the design. A google of Nerotech finds no results for me.

PPS there is a font called Neo Tech that I quite like. http://www.myfonts.com/fonts/mti/neo-tech/
 
Just as an aside, the Quad 306 amp looks good but the layout is terrible. the signal tracks appear to run straight through the power supply. Sometimes neat isn't the best.
 
mudlark said:
you need to be careful about upsetting the trademark holders and heed audio in particular. I don't think you are in the same market at present, but the quality of your stuff could easily end up with going into some sort of low level production. I would guess that your amplifiers would be in a small area of a niche area, but you never know.

The amplifier is in effect a Nytech clone with improvements. There have been other companies that have done well using a standard circuit with improvements. And I don't mean our friend from Chesterfield.

You need a name for the amp that works. Newtech being a poor example. Perhaps Neutech, it looks better. (That ends my knowledge of german - excepting Ein grosse bier bitte!) You could risk "your name" - a nytech clone. At least you are being honest.

Other successes have been quad clones, such as Netaudio and Quad spot /Dada electronics in the netherlands.

In any case good luck.

Mike

PS You've acquired the name nero for the power supply. Perhaps "Nerotech - courtesy of Nytech". That does the german input with a british "tip of the hat" to the originator of the design. A google of Nerotech finds no results for me.

PPS there is a font called Neo Tech that I quite like. http://www.myfonts.com/fonts/mti/neo-tech/
Click to expand...

Thanks for your comments Mike,

I like the font. Specially in medium bold italic .... Looks great :cool: Actually I'm looking for a possibility how to print the Front of my cases. But what I know so far, it seems to be very expensive for 10 boxes with different prints on ....

It's not my intention to sell my Amps. It's not commercial, it's just a crazy idea from myself to tune my old 30year old Nytech Equipment. The PCB's I have are mostly damadged and it's difficult to repair them. My local dealer here told me several times, that I have to change to other equipment and want's to sell a used EINSTEIN to me. And also HEED does not follow the active way. I asked the German distributor about an active cross over to combine with the HEED-PM's. The have not the intention to do it.

To stay with my ARC's and follow the active way I had no other choice to repair my good old Nytechs and decided to make new PCB's. And by doing this, I want to improve them .... And following this raod, you are right, it will be a Nytech 602Clone.

And I love the name Nerotech, but it's very close to Nytech, and that's the reason, I followed the NERO - Road.

By starting to develope the cloned PCB, I've got real fun in what I'm doing. And I decided to tune my whole equipment. And the idea behind is: To do it in the best way which is possible, which best components, and improved logic ......

And the names I want to use are as following:

NERO PSU (The PCB for the NERO SA-1)
NERO SA-1 (Stereo Amplifier - 1 / The Nytech 602 Clone) will be later replaced by 4 Mono-Blocks ....
NERO MA-1 (Mono Amplifier - 1 / Monolized 602 Clone)
NERO PRE 42.5 (Another vintage project I'm preparing for a Pre Amplifier together with someone here out of the forum ... )
NERO SP (Super Power - An external Power Supply for the PRE 42.5)
NERO PP (X-ONO based Phono Pre)
NERO PPP (External Power Supply for the Phono Pre)
NERO XO (Discrete Linkwitz/Railey electronic Crossover for my 30 years old ARC 050)
NERO ADAC (32/384 Analog Digital / Digital Analog Converter, also a new Project we are planning)

There are some crazy ideas behind. E.g. a Pre which can be controlled with an iPad.....

So, thats the situation .....

And "Ein grosses Bier bitte .... " is a very important sentence :cool: You have to add "kalt bitte - cold please" :D

Regards from Germany

Ingo
 
Ingo,

There's nothing attractive about NoiseTech to my ear. What about MyTech.
Also IngoTech sounds like Imotep from the Mummy movie. Maybe some theme there.

David
 
It's progressing ....

tLGnr.jpg


The PSU's are finished.

Tomorrow I get new Toroids for my 602's with 2 x 58V ..... Then I will assemble it ..... and will listen to the difference ;)
 
Nice looking power supplys;) when you put them in the case put the diodes facing the transformers rather than close to the amplifier boards as the diods are quite noisey

Alan
 
337alant said:
Nice looking power supplys;) when you put them in the case put the diodes facing the transformers rather than close to the amplifier boards as the diods are quite noisey

Alan
Click to expand...

Good Tip :cool: Will work in the new boxes, in the old one side is near the amplifier board ....

You can see it here:
CmHmB.jpg
 
New Trannies arrived ....

kIuo3.jpg


300VA 2 x 55/59V .......

And the new Double Rail Power Supply Board ....

Tomorrow I know more ...
 
Short update:

New PSU supplies 77,5V on both rails. Now the CPA602 is - more or less - a dual mono designed Stereo Amplifier.

CPA 602 - S/N: 11111 ... Sucsessfull update ....New PSU works ...
CPA 602 - S/N: 10943 ... Update failed .... Power Amp boards burned .... both. This is the one which was recapped and the circuits were changed. No chance so far to get it back to life ....

Stepped back one step, good to have the passive crossovers for the ARC050 ....

First listening impression with working 11.111: I can see more details on the stage ... even with the passive crossover.

Now I need to speed up the new PCB's for the first NERO .... Will be also a repair kit for burned CPA 602's .... 11.111 works perfect together with the new PSU ....

I'll post some pics tomorrow ....
 
337alant said:
Nice looking power supplys;) when you put them in the case put the diodes facing the transformers rather than close to the amplifier boards as the diods are quite noisey

Alan
Click to expand...

So far as I'm listening, I can see no noisey diodes .....

The bass is more precisely as before ...
 
As promised, some pics from yesterday evening:

New and old PSU PCB's ...
Qv5uS.jpg


New PSU PCB and new Toroid in good old CPA 602 ....
5GDIf.jpg


kkSXn.jpg


This one burned ...
vMX5k.jpg

S/N 10943
On boath amp boards R17 looked like coal ...... There is an issue with the common ground of both rails ....

R17 were replaced and we see light at the tunnel that we bring Burnie2 back to life soon ......
 
Short update ....



NERO Box Prototypes arrived ..... need some fine adjustments, but result can bee easily seen ....



That's for the CAP602-Clone ......



svRbV.jpg




w8tLF.jpg




mrBWy.jpg




Imt2x.jpg




OH6Gy.jpg




Vxqzn.jpg




MjL0o.jpg




So, please give me your comments ..... and I know, the painting can be improved. And it will be ......
 
As the next step I'll give the new 602's boards to production. Again they will be black, with 105um Copper, and chemical aurum surface ...

Actually I'm looking for the right components. Any suggestion for the resistors I should use? 5%, 1% or 0.1% Tolerance? Which Brand?

What about capacitors: ELNA SILMIC II, PANASONIC NHG, FROLYT ???, NICHICON ....
 
Bit of a shot-gun question. All the low power resistors were probably originally 5%. One percent metal film, typically blue, are the norm today. Possibly some were or should be matched closer, eg in the arms of a long tail pair. Power resistors are typically wire wound. Worth matching the emitter resistors to the same tolerance as the output device's Vbe. Or at least there is some relation between the two. MarkT was able to hear an improvement using power metal oxide film resistors. Big Caddocks come to mind.

Caps need to be considered according to position in the circuit.

David
PS everything looks vey handsome, very professional.
 
bivalve said:
Caps need to be considered according to position in the circuit.

David
PS everything looks vey handsome, very professional.
Click to expand...

Here's the List of the Caps I want to use .....

oqqkJ.jpg


For the resistors the idea is to go with sorted Vishay Dale 1%, as precise as possible according the original Values.
 
Hi,

Dont know the Nichicon FW range. All the rest will be a reasonable first choice. Here's a couple of comments:
C5 feedback cap - some use 2x68uF Wima Film caps
C7 Schematic shows .001uF, table .01uF. Not sure of its function but FKP2 should meet any chalenge
C11 looks like a PS decoupling cap. I would expect ~10uF

C4 and C5 are are signal coupling caps. They might have low enough voltages to use Wima MKS2-5mm pitch polyesters. Elsewhere how did you decide to use Pana FC or Silmic II? they are both low impedance types with performance holding up to 100kHz. In your circuit both types are used for PSU decoupling.

David
 
bivalve said:
Hi,

Dont know the Nichicon FW range. All the rest will be a reasonable first choice. Here's a couple of comments:
C5 feedback cap - some use 2x68uF Wima Film caps
C7 Schematic shows .001uF, table .01uF. Not sure of its function but FKP2 should meet any chalenge
C11 looks like a PS decoupling cap. I would expect ~10uF

C4 and C5 are are signal coupling caps. They might have low enough voltages to use Wima MKS2-5mm pitch polyesters. Elsewhere how did you decide to use Pana FC or Silmic II? they are both low impedance types with performance holding up to 100kHz. In your circuit both types are used for PSU decoupling.

David
Click to expand...

C5: I like the idea. There is a 220µF with a tolerance of 5% ..... but they have 37mm pitch. This I don't have on my new PCB's as they should fit also in an old CPA602. I'll put this to my parking lot for the Mono-Design.

C7: Yes, you are right, there was an mistake. Original schematics of 602s shows 0.01 ...

C11: Original schematics shows 0.1 ....

C4: Original schematics shows 10µF 50V and
C5: 100µF 50V ..... this was changed to 470µF as this is changed on the NEXUS and Obelisks to 470µF. At least this could be two parallel 220µF with 5% tolerance. Also for the 10µF should be a WIMA-Replacement possible. But how the sound will change?

As I understood, C4 and C5 are in the signal path and important for the sound. Because of this, they will be Simlmic 2. From my google-studies I now, tha the FC's are the better choice for PSU-Decoupling. This is the reason why I selected the above cap's .... The question is, is there agood alternative to the ELNA's? Nichcicon FG?

- FC's for PSU ....
- ELNA for Sound ...
- Film Caps with the lowes tolerance I could get to replace ceramics .....

Thanks for your good comments David. One idea more on the parkling lot for the Mono-Design ...

Regards from Germany

Ingo
 
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