API 312 Thread!

[Bauman]

Yea, I never saw a VU circuit connected to that output. Just left it there with hope to figure it out later...

I have seen (on api212) the VU takes its signal from the output of opamp, and it uses a LM3915 to the task...

Is there any good VU thread? I wanted to check whether I could get a bunch of the same VU for different projects. (312, Forrsell Opto, SSL Bus Comp, and probably What and 1176 somewhere down the line.) As I try to contrive my packaging, it comes up as an issue.

Maybe a VU-META??? I´d be great to see all the info about VUs in just one place...

:guinness:
Fabio

 

[CJ]

Meta VU might be too specialized,

how a bout a

Meta VU's--Pads--Attenuators--Faders--XLRs--etc thingy?

Since they deal with the front and back of the circuit?

 

[pmroz]

meta for i/o / adj / metering... great idea

..off topic, but... didn't Tony have fake fingertips?

 

[CJ]

yes on the fingers, how do you think he does those hammer-on's so good!

accident at a sheet metal shop the day before he was to join Tull. :sad:

Thank God he had that accident!
:guinness:

 

[Bauman]

how a bout a

Meta VU's--Pads--Attenuators--Faders--XLRs--etc thingy?

Even better! :thumb:

 

[Greg]

Fabio:

I had intended to use a switch for the gain control, but I recently bought six 22k reverse log pots :grin:. I'm thinking that as long as I don't have the 1x12 switch in the board, I can just hook up pot in there as well. The resistors are just hanging off as an open circuit... right?

What do you think?

 

[dukasound]

[quote author="Greg"]Fabio:

I had intended to use a switch for the gain control, but I recently bought six 22k reverse log pots :grin:. I'm thinking that as long as I don't have the 1x12 switch in the board, I can just hook up pot in there as well. The resistors are just hanging off as an open circuit... right?

What do you think?[/quote]
Hi
If we use 1x12 switch for Gain Fabio said that every position is 4db from 32db-64db. What with 20K rev Log. Is it from 0db-64db, 32db-64db or otherwise.
I need it for making front panel.
Duka

 

[Bauman]

I had intended to use a switch for the gain control, but I recently bought six 22k reverse log pots . I'm thinking that as long as I don't have the 1x12 switch in the board, I can just hook up pot in there as well. The resistors are just hanging off as an open circuit... right?

Right Greg! You just need that jumper next to RGx resistors on.

Duka,

Minimum gain, even with a pot is: 20dB from 1:10 input trafo + 6dB from opamp + 6dB from 1:2 output transformer, total of 32dB min. For max, is 20dB + 40dB + 6dB = 66dB

Carnival DIY:

http://www.thediypill.phx.com.br/api312/r312_4_frontal.gif
http://www.thediypill.phx.com.br/api312/r312_4_top.gif
http://www.thediypill.phx.com.br/api312/r312_4_side.gif

I hope I get better on drilling :roll:

:sam:
Fabio

 

[Rob Flinn]

Don`t forget to put the phase reverse links on board 2.

Looking good Fabio

 

[mhartung]

Hey Fabio,

those look great! I was wondering if ther is room for the DI input on the front panel on either sideof the gain switch???

mike

 

[pmroz]

Fabio, those pres are looking great!!! Are all those cinemags the same? Curious about 1:8 vs 1:10... 1:8 maybe less padding.

What's the spec on that large component top right, enclosed in al can?

...if ther is room for the DI input on the front panel

...with DI-in, and 1/4in cable connected... might be hard to turn switches.

 

[fum]

Fabio,

That looks awesome! It's funny how I'm starin at almost the exact same project in front of me.

The only difference is I'm using 312 boards, and I chose black inserts on grey knobs, with different switches.

crazy =)

ju

 

[Bauman]

Don`t forget to put the phase reverse links on board 2.

Thanks Rob! There´s a transformer missing also.

Mike,
Looks kinda busy to DI but maybe next to the Gain knob... :roll:

Paul, all Cinemags are the same, CM75101APC... that is the cans.

:guinness:
Fabio

 

[louder]

alo
fabio,that`s it.
nice,very nice.
as i`m using pot`s,i`ll have more room to di.
whish i ordered more boards, so i`d have more diy.
best regards
pedro

 

[dukasound]

Duka,
Minimum gain, even with a pot is: 20dB from 1:10 input trafo + 6dB from opamp + 6dB from 1:2 output transformer, total of 32dB min. For max, is 20dB + 40dB + 6dB = 66dB
Fabio

OK. I will use 1:8 Jensen JT-110K-HPC. I think I got about 18db from input trafo, than I have gain from 30db-64db. Am I right?
Duka

 

[pmroz]

...no i meant the one in full-frontal shot... itaipava? what windings that one got?

 

[Bauman]

aahh ok! That can! :razz:
I couldn´t wait to celebrate so I´m working and celebrating at same time :thumb:

 

[Rob Flinn]

I just tried bench testing an API setup that I made using Fabio`s board design & the Melcor op amps. I have Sowter output & Parmeko input transformers.

If I feed a sine wave into it I`m getting a lump on part of the cycle.

Has anyone had this sort of thing happen ? Got any ideas ?

 

[Guest]

[quote author="Rob Flinn"]I just tried bench testing an API setup that I made using Fabio`s board design & the Melcor op amps. I have Sowter output & Parmeko input transformers.

If I feed a sine wave into it I`m getting a lump on part of the cycle.

Has anyone had this sort of thing happen ? Got any ideas ?[/quote]
Is that the same lump that Fabio had?
I think he has some piccies on his 312 site
http://www.thediypill.phx.com.br/diy_api312.htm
Hafl way down the page - some sine wave oscillation

 

[Rob Flinn]

Thanks Simon

Yes, exactly that sort of thing. I`ll have to mess around with the caps, to match my aged Parmeko transformers.