Tweekhead

Re: APP discreet op amps
« Reply #300 on: November 19, 2010, 01:00:08 PM »
Pier,

I received the 2 germanium DOAs today and plugged one in for a quick test. It sounds fantastic! I can't wait to try it out on electric guitars. Thanks for the great product, and I apologize for the drama, but seeing as we are unfamiliar with each other, and I only had 45 days for recourse from Paypal I had no other choice.

Thanks again,

Arthur


ppa

Re: APP discreet op amps
« Reply #301 on: November 20, 2010, 04:55:13 PM »
thank you to having bought from me and for comments.
Pier Paolo

ppa

Re: APP discreet op amps
« Reply #302 on: November 22, 2010, 01:17:47 PM »
This is the APP1040 module.
APP1040 pre has a new topology to avoid electrolityc caps in the amplification stage.
It has the DOA's positive input pin directly connected to the DI, as is in the API3124 to do an example.
It is designed for APP DOA's , 2520 , 990, Forsell DOA's and MM99 and others.

I have posted the prototype pics here http://www.groupdiy.com/index.php?topic=33576.240

APP1040 is not a 312 but a new project to be clear, who knows my opamps can have an idea of its performance.
APP1040 can use several trasformers from: Lundhal, OEP, ED trasformers, Altran, jensen , cinemag, JLM, Sowter.

  
 
« Last Edit: November 29, 2010, 02:33:03 PM by ppa »

creal

Re: APP discreet op amps
« Reply #303 on: December 10, 2010, 09:40:05 AM »
Hello Pier Paolo,

Pm'ed you
I'd like 4 APP2050 for the make up gain in my solid state pultec.

Creal
« Last Edit: December 10, 2010, 09:43:16 AM by creal »

deuc224

Re: APP discreet op amps
« Reply #304 on: December 11, 2010, 06:31:24 PM »
It has 32 DB of gain?

ppa

Re: APP discreet op amps
« Reply #305 on: December 11, 2010, 06:43:19 PM »
no, it isn't. Its gain depends by trasformers' ratios, the resistors used in the NFB net and the DOA used.
However with an APP2050, the Classicapi input an output trasformers the standard setting gives 64 dB of gain.


 

creal

Re: APP discreet op amps
« Reply #306 on: December 16, 2010, 05:15:51 AM »
Hello Pier Paolo,
Paypal'ed for the  DOA APP2050 this morning

Creal

ppa

Re: APP discreet op amps
« Reply #307 on: December 16, 2010, 05:28:18 AM »
Hello Pier Paolo,
Paypal'ed for the  DOA APP2050 this morning

Creal

thanks
Pier Paolo

delphi

Re: APP discreet op amps
« Reply #308 on: December 16, 2010, 11:19:42 PM »
I am building 12 of Mitsos 312/990 preamps. I have used JLM DOA's for 4 of them and want use your DOAs for 4 more "2050" types and 4 for a 990 type.

Which of your DOA's do you recommend for the Mitsos design.If all of your 2050 types are OK for this design (I dont want to use servos) - then I would appreciate a comment on the subjective "sound" of each of your DOA's so I can "mix and match.  The 990 versions will all be using 1:2 ratio input transformers, whilst the rest are using 1:5 or 1:6. What would the FB resistor value need to be with a gain pot of 10K? _ I seek a total gain of 60db or better
All generalizations are false

ppa

Re: APP discreet op amps
« Reply #309 on: December 17, 2010, 09:39:14 AM »
I am building 12 of Mitsos 312/990 preamps. I have used JLM DOA's for 4 of them and want use your DOAs for 4 more "2050" types and 4 for a 990 type.

Which of your DOA's do you recommend for the Mitsos design.If all of your 2050 types are OK for this design (I dont want to use servos) - then I would appreciate a comment on the subjective "sound" of each of your DOA's so I can "mix and match.  The 990 versions will all be using 1:2 ratio input transformers, whilst the rest are using 1:5 or 1:6. What would the FB resistor value need to be with a gain pot of 10K? _ I seek a total gain of 60db or better

I make a version of JE990 I called APP99. This one is similar to JE990, there're differences in the frequency compensation circuit.
My 99 has a new circuit that does not use any inductance (used inside 990 in the 1st stage) and also gives great stability, this new circuit is the same used in the APP2050. The other difference is in its front-end that uses two discrete ultra low noise mached transistors insted the LM394. Moreover, the transistors inside are different types. This APP99 can be used with 1:2 input trasformers.
APP99 run in the mitsos preamp with servo or with out cap.
regarding the pot I am seeing for it.


APP2050 runs in the mitsos preamp set in 312 mode without servo, can be used input trasformers with ratio from 1:5 to 1:10 , I council the 1:7 classicapi in trasformer.

I will you all indications to set the mitsos preamp with APP99 and APP2050 opamps.









JBVries

Re: APP discreet op amps
« Reply #310 on: December 18, 2010, 07:22:08 PM »
Got my 6 PSU boards and I gotta say the quality of these things are absolute tops. Thanks for the great power solution!
A little bit of the sonic mayhem I bring to the table.....

http://www.soundcloud.com/jbvries

ppa

Re: APP discreet op amps
« Reply #311 on: January 03, 2011, 10:18:35 AM »
this is the APP1040's PCB

ppa

Re: APP discreet op amps
« Reply #312 on: January 03, 2011, 10:24:45 AM »
and this is the APP meter2 , this meter is usable with the APP1040 board and with other pres.
Meter2 is based on the LM3915 by National and drives 10 leds, but who want can use less leds.
This board has power supply voltages   in range +- 16V to +-24V.
With the multiturns trimmer can be set fine the 0 dbu led.
 
  
« Last Edit: January 05, 2011, 02:41:00 PM by ppa »

ppa

Re: APP discreet op amps
« Reply #313 on: January 03, 2011, 04:41:45 PM »
and this is the meter2's pcb

dalmaproductions

Re: APP discreet op amps, LED Meter, PSU board.
« Reply #314 on: January 09, 2011, 08:29:32 AM »
Hi Paolo,
I've tried to contact you via email, and via PM with no success. My email gets: "Delivery to the following recipient failed permanently..".

Is there an email address I can contact you at? Send it via PM please.

Miguel

ppa

Re: APP discreet op amps, LED Meter, PSU board.
« Reply #315 on: January 09, 2011, 09:58:44 AM »
you may contact me to  AMSMicro  [at]  katamail  [dot]  com    , thank you

kepeb

Re: APP discreet op amps, LED Meter, PSU board.
« Reply #316 on: January 13, 2011, 12:00:09 AM »
hey
like the look of your new vu.
do you have a BOM?
pyinag cosle aentttoin

ppa

Re: APP discreet op amps, LED Meter, PSU board.
« Reply #317 on: January 15, 2011, 05:59:47 PM »
the meter2's schematic

creal

Re: APP discreet op amps
« Reply #318 on: January 17, 2011, 12:10:47 PM »
Hello Pier Paolo,
Paypal'ed for the  DOA APP2050 this morning
Creal

Hello Paolo,

Any news about the 4 DOA?
I still waiting 2 of them for finish my EQs.
I have a question, do you think, it's a good way to make a 325 API clone as Makeup gain amp for the meq5?
I need 16db gain.

Thx
Cyril 

ppa

Re: APP discreet op amps, LED Meter, PSU board.
« Reply #319 on: January 17, 2011, 03:38:28 PM »
Scuse me for the time, but I am yet waiting the epoxy resin to pot your opamp and other 40.

however these 4 are new SMD version using panasonic metal film resistors in the signal path (very very good resistors), and this nwe version sound much better than the previus. It has a very realistic guitar, for example, with realistic ultra fast transients. Sorry, they need another week to send them.

For Makeup gain you could use a 325 api clone or, if you want, an APP1040 board without input trasformer using its DI input.