APP Studio Ing's products - APP992 - APP14GE Germanium DOA and other kits

Glad we cleared that up! Thanks Udo and Pier!

dingo said:

hello!
this is a new gyrators equalizer, it has been designed by PPA(Pierpaolo) for500rack
He has sent me 4 prototype pcb 's and  I have assembled them with his schematic.

It uses old and modern inedit discrete  topology using doa's
the gyrators use germanium transistor
it sound great! i like it so much.

This eq has a vintage sound -mids, basses are very good but high are fantastic
it has the particularity to not change the features of the sound at max boost/cut as an eq should do.
Moreover, with max gain you don 't keep noise or garbage,very quiet gear

I don't know if Pier Paolo has intention to put it inthe diy market, you shoud ask him!!
dingo.

here with his big brother..

Click to expand...

hello!

interesting EQ, is there more info available? could Pier Paolo maybe elaborate?

Feature wise its something i've been looking for. Sound wise, can't be bad

thanks!

Hi,
thanks for the interest on the eq,
It has 3 bands and 6 frequencies per band.
The first 5 of these  frequencies of each band are similar to those of the 550a.
This eq uses two DOA's and 3 germanium based gyrators.
Actually I have not intention to put it on the market, but I should have some prototype PCB's.
BTW if you want, you may send me an email so I could send you better details on it.
best regards
Pier Paolo

A little while ago I finished a dual channel helios 69 using Ian's filters and the io board for the make up. Its fantastic.  Incredibly versatile with being able to switch between various DOA's and IC's. Its a keeper. So thank you Pier. I think I might have to try your 1040s. I'll pm you.
Dylan

thanks very much for comments on I/o board,
I am going to read your pm.

Your APP14GE  germanium DOA sounds promising. Is it a drop in for an api312 gar2520? What voltage would it like to see?

thanks,

mrcase said:

Your APP14GE  germanium DOA sounds promising. Is it a drop in for an api312 gar2520? What voltage would it like to see?

thanks,

Click to expand...

thanks very much for interest

Yes, APP14GE can be used inside a 312 preamp.
I have designed it for a power supply voltages from dual 14V to dual 25V.
I have sold a few of pcs before posting in GDIY and they run inside 312 clone preamps too.

Pier Paolo

ppa said:

mrcase said:

Your APP14GE  germanium DOA sounds promising. Is it a drop in for an api312 gar2520? What voltage would it like to see?

thanks,

Click to expand...

thanks very much for interest

Yes, APP14GE can be used inside a 312 preamp.
I have designed it for a power supply voltages from dual 14V to dual 25V.
I have sold a few of pcs before posting in GDIY and they run inside 312 clone preamps too.

Pier Paolo

Click to expand...

Can I see a picture of one?

just a photo.

This is one of the prototypes

I have built a number of the APP14GE and though I have yet to do some critical listening to them, I did test them in a CAPI VP25 module and they worked perfectly.

a better photo of the app14ge

Hi Pier

Sent you an email. Down for a few doas!
Thanks!

Payment sent. Thanks for the invoice.

How would you describe the difference sonically between the new APP14GE and your 992?

rob61 said:

How would you describe the difference sonically between the new APP14GE and your 992?

Click to expand...

APP992 is very trasparent with a bit a fet background, very high dynamics, with "expensive elegant sound" as some diyers said me. I am using all words of who use it.
I have designed it for line stages for S/N and THD upgradings, for who want a trasparend but not ice sound.
It has both an ultra low voltage noise with a an ultra low current noise, much better than famous IC opamps.
Very high slew rate and bandwith and top high stability for eqs, unbalancing stages and IV converters for DACs.

APP14GE is an mixed vintage and modern design to have modern performances with vintage sound with germanium color.
Very warm sound. And thick.

APP14GE can run both a +-16V and -+24V of power supply.

Hello Pier Paolo,
I would like to ask you why did you discontinued the 2050 op amp?

I loved those op amps and would like to buy more, was amazed when I saw you were not selling them anymore

thanks

thanks for your feedback 
I discontinued the APP2050 when I  started the APP992 sale as people bought  mostly the APP992 than the APP2050, probably, because they supposed maybe that the APP992 was better.
The matter is that these ones are simply different between them. Who had previously bought the APP2050, he bought as the APP2050 again, but was a strong internal competition the same.

How many pcs you would need?

Hi Pier Paolo, I'm doing a 4 channel 321 type build, I had 2 never used 2050 opamps that I was keeping and wanted to buy 2 more.
Although something is wrong with my opamps.

Will send you and email
thanks

Hi Pier

Got the kits. Looking good.

thanks!

hi,

i'm interested in the germanium DOA. I was thinking of using my own germanium transistors which I have stock of from past projects - is it best to test them before they go in? Will a "leaky" transistor be OK in the DOA or should I find "stable" germanium transistors for the DOA?

Thanks