Re: [BUILD] CAPI VP2X~500 Series~Preamp Kit~Official Support Thread
« Reply #980 on: March 15, 2020, 04:15:07 PM »
This will be fine. Just caps charging. We are basically looking for a direct short which you do not have so carry on!

Ok, thanks. I assembled two of these a few years  ago and I don't remember this happening.  Also I think the solder pads were bigger back then.


Re: [BUILD] CAPI VP2X~500 Series~Preamp Kit~Official Support Thread
« Reply #981 on: April 24, 2020, 06:35:13 PM »
I just finished my 9th preamp and the first vp26 stepped gain. Everything seems works fine but I have a question.
Since I have no way to check the sound  with  fancy machines (of course I checked the testing point first), I just load the pre with 2 mics (matching pair), and do a little recording. Nothing weird  so far.
Right now during this quarantine I have available just another vp26 variable gain. After testing I noticed a little difference between the two.
The stepped one has a tiny bit more output gain at the same level (thing I 've already noticed between other Vp stepped gain models) but the strange thing is that always the stepped one has more proximity. the tone is exactly the same (at least at my ears). Is not even presence, is more like, when you move the mic far from the source, is more noticeable on the variable gain then the stepped gain. And getting a sound from a close source seems the stepped has more presences.
I swiped the mics and re did it, and the result still the same, so they are a real matching pair  :D

Now, those thing are not really bothering me since both of them sounds awesome, I'm just looking for tips and confirm  those difference if somebody else had the same experiences.

although I did apply a little modification on the build, maybe you can give me a tip also on this one. For some reason (I'm not going to explain here since I already wrote too much), I applied pins to the output transformer cable. I checked before installing the ohm of the cable with and without pin and saw that was the same, so I decided to go for it. Obviously the result is that the preamp works, not sure if the pins are making actually difference here (pic is attached)

My question is:  did anybody noticed those differences like me between those 2 preamp?


jsteiger

Re: [BUILD] CAPI VP2X~500 Series~Preamp Kit~Official Support Thread
« Reply #982 on: April 24, 2020, 09:25:51 PM »
....The stepped one has a tiny bit more output gain at the same level....
I think you mean the stepped gain version appears louder when the knob is set to the same physical position as a variable gain preamp? If that's what you mean then likely yes as they are completely different tapers and were never intended to be the same.
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Re: [BUILD] CAPI VP2X~500 Series~Preamp Kit~Official Support Thread
« Reply #983 on: April 24, 2020, 09:32:44 PM »
I think you mean the stepped gain version appears louder when the knob is set to the same physical position as a variable gain preamp? If that's what you mean then likely yes as they are completely different tapers and were never intended to be the same.

Yes exactly what I meant!
I noticed between the variable 26 and the stepped 25, 312 but I was not sure till now.
So for the rest I guess is all fine and the socket won’t affected the output transformer.
Thanks Jeff

zonkola

Re: [BUILD] CAPI VP2X~500 Series~Preamp Kit~Official Support Thread
« Reply #984 on: June 19, 2020, 07:25:22 PM »
Aloha! For my first post I have an esoteric VP25 question:

I have two Cinemag CM-75101A input transformers and two Cinemag CMOQ-2s output transformers that have been sitting in a drawer for a decade, and I'm looking at the VP25 no-iron kits thinking, hmmm...

(I've built a CAPI 500 rack, two VP26, and have a BT50 on the workbench now, so I'm up to speed on the CAPI basics.)

I found the thread that discusses the CMOQ-2s and it looks like it's just a matter of wiring it up correctly due to the differences in the primary & secondary windings compared to a CA2503. But what about the CM-75101? Has anyone used one in a VP25 and lived to tell the tale?

Re: [BUILD] CAPI VP2X~500 Series~Preamp Kit~Official Support Thread
« Reply #985 on: June 19, 2020, 07:56:55 PM »

I have two Cinemag CM-75101A input transformers and two Cinemag CMOQ-2s output transformers that have been sitting in a drawer for a decade, and I'm looking at the VP25 no-iron kits thinking, hmmm...
[/quote]

try to buy the no iron kit first...

zonkola

Re: [BUILD] CAPI VP2X~500 Series~Preamp Kit~Official Support Thread New
« Reply #986 on: June 19, 2020, 08:55:58 PM »
try to buy the no iron kit first...

I know they're out of stock now, but I assume they'll be available eventually. Will the 75101As work in the VP25 circuit without major surgery, perhaps by replacing C2 and R4 with a 150K resistor?
« Last Edit: June 20, 2020, 12:00:13 AM by zonkola »


 

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