my A-P-I preamps (with sound samples)

I'v finished 2 channels of API-like preamps.

Here are some photos:







My own pcb's, 75101APC input transformers, CMOQ-2S outputs,
and opamps made from fabio's 2.5.2.0BC boards...


I did some recordings for comparing the 2.5.2.0BC with the original 2520 opamp (black, new one)...
I'v used a dynamic mic with Y-cable that goes into both channels,
and placed an original API opamp in one of the channels.
Both channels were calibrated to the exact level.

Original API opamp (acoustic):
http://www.freewebs.com/upa-audio/API_ACOUSTIC.wav

2.5.2.0BC (acoustic):
http://www.freewebs.com/upa-audio/UPA_ACOUSTIC.wav


Original API opamp (electric):
http://www.freewebs.com/upa-audio/API_ELECTRIC.wav

2.5.2.0BC (electric):
http://www.freewebs.com/upa-audio/UPA_ELECTRIC.wav



Comments are welcomed....

Udi.

Beautiful work!!! I'm envious!!! :green:

Udi,
nice and clean work :thumb:
great frontpannel - but why did you do the phantom switch for both channels ?

Beautiful work!!! I'm envious!!!

Click to expand...

Thanks...

great frontpannel - but why did you do the phantom switch for both channels ?

Click to expand...

Well, I'm asking that question my self two..... :grin:


Udi.

I like the detail of the boxes around the controls and mounting the
jacks on the inside.

Nice work !

The repros sounded a little more mellow [ to me on the laptop ]
thanks for taking the time to do that

reagrds Greg

And just for fun guys, 2.5.2.0BC vs NE5534:

5534:

http://www.freewebs.com/upa-audio/5534_AC_02.wav

2.5.2.0BC:

http://www.freewebs.com/upa-audio/UPA_AC_02.wav



Udi.

Mazal Tov Udi..... very nice job.. :thumb:

Mazal Tov Udi..... very nice job..

Click to expand...

Toda peter...



Anyone about the sound samples???


Udi.

[quote author="[silent:arts]"]Udi,
nice and clean work :thumb:
great frontpannel - but why did you do the phantom switch for both channels ?[/quote]

Stereo!



My old API 3124 has one sw for all four chnls, and my old 3124M has no sw.

Thank for doing sound clips!

I think the DOAs definitely sound like "the same product", the API is slightly brighter/more open on the electric, on the acoustic the difference is to small to describe. There is very little residue when I invert one of the channels.

Good job, my guess is that the same differnce could be found between two APIs.

[quote author="udip"]I'v finished 2 channels of API-like preamps.
....
Comments are welcomed....

Udi.[/quote]