italian style

[Stee]

http://translate.google.com/transla...autocostruiti.htm&sl=it&tl=en&history_state0=

 

[Stee]

Stee italian Style

CEFP
CFP + EF Output Stage

better use NTE37MCP as Final

NTE36(NPN) + NTE37(PNP) Matched Complementary Pair

TOSHIBA 2SA1930 + 2SC5171 as driver

 

[Stee]

Chet Amp application

see this complete schematic

 

[Beto]

congratulations on the excellent project which the values of bias adjustment to 60ma. I can change the value of
R109 = 470r for trim-pot for 1k to set off-set.

 

[Stee]

Thanks a lot Beto

now there is version 2
ready to test

http://www.esafono.it/rotel.pdf

 

[jaycee]

The first circuit is simply Musical Fidelity's A1 power amplifier redrawn, without component values.

The "Chet Baker" Amp is a Rotel clone with a slightly different output stage - the graphics used for the schematic, style of compensation, plus the choice of transistors is identical to many Rotel service manuals.

 

[Symon]

The Chet Baker schematic has a Bryston style output, which can be tricky to keep stable.

One thing the 0.22 resistors in the collectors of the CFP output devices serve no purpose. I think they should be moved to the emitter side.

I'm interested to hear if it works

 

[Stee]

Thanks Symon

can you post a Bryston style output schematic example?

see the source of this idea:

http://www.esafono.it/ccc.pdf

 

[Symon]

there used to be a technical description on hte bryston web site, but can't find it right now.

take a look around the site.

Bryston Technical

this is the schematic of a Bryson amplifer

Bryston Schematic


You can also find discussion on Bryston amplifiers here on DIYAudio ..

 

[Beto]

In the original project could not a good result
modified some parts in the scheme to operate the simulator see the components changed:
R103 and R113 = 47k
R115 connecting a capacitor of 220uf to the ground.
R127 = 2k
Vr103 = 1k
R125 = 1k
q107 put capacitor 22pf of B / C.

 

[Stee]

Thanks Symon

Thanks Beto
what say your simulator about performance?

 

[Beto]

In the original project could not a good result
modified some parts in the scheme to operate the simulator see the components changed:
R103 and R113 = 47k
R115 connecting a capacitor of 220uf to the ground.
R127 = 2k
Vr103 = 1k
R125 = 1k
q107 put capacitor 22pf of B / C.

 

[Beto]

Stee the simulator seemed ok but I want good opinion of other friends of the forum here because the simulation was done with some changes and to make sure the quality of the amplifier will have to mount the project.
simulation found in the high THD.

 

[Stee]

ultra very good

probably Q10 AND Q12 need resistor on collectors
like modern CFP

can you post the PCB
that I can order on ebay?

 

[Beto]

STEE the design of the card did not because I am not very good at drawing card. the design and simple to assemble a 4,256 points in placaProtoboard Islands 10x30cm.

 

[Stee]

hi hi

nice!
I believed that the same simulator generate design...

what do you think about position of resistors 20/21?

 

[Beto]

R20 and R21 in the emitter because the problems in the simulation showed bias when in ultilizado collector.
may be some bug in the simulator and not 100%.
Mounting the project in practice show the reality of the project

 

[keantoken]

Beto, your schematic looks off. Look at Q13's base. Shouldn't this be connected at Q8's emitter?

- keantoken

 

[Beto]

Ok Keantoken the right and in turn the basis Q8 emitter.
you are correct. thanks

 

[keantoken]

You're welcome.

- keantoken