[BUILD] CAPI VP28~500 Series~2-Stage Preamp~Official Support Thread

[kante1603]

Money,money,money........will take a while,but I already thought this "direction".
What I already have is rack full of compressors that will reside under the preamps.
These will form a killer front-end for my next musical where I'll have 8 lead vox accompanied by a lot of backing vox on their radio mics (yes,I use my diy gear live,too!).
Budgets are getting lower,and I'm sure I will only have digital consoles for the next projects.
I don't like them soundwise,so I'll have VP28s and LA500s on the line-inputs and won't use their mic pres.
Best of both worlds:Consoles with snapshot- automation and my private gear for the real sound.Not bad.....

Best,

Udo.

 

[sharpeleven]

Just wondering if anyone else noticed a slight change in transient response between the -6 and -12 setting while all filters are bypassed. So even with with no cutoff freq selected, the -12 / -6 switch is somehow always active and seems to have a significant influence on transient response. I have built 5 units so far and they all behave the same way.

I'm not saying that anything is broken, I actually kind of like having yet another option available to shape the tone. Just haven't seen it documented anywhere and no mention of it.

The -6 setting (switch in upward position, filters bypassed) sounds slightly more 'in-your-face'. I like the -12 setting (filters bypassed) when going for slightly slower transient response, to move things backwards a bit.

With all the different options available for tone shaping the VP28 quickly turns out to be a Swiss-army-knife kinda device.  8)

 

[tonycamp]

Just wondering if anyone else noticed a slight change in transient response between the -6 and -12 setting while all filters are bypassed. So even with with no cutoff freq selected, the -12 / -6 switch is somehow always active and seems to have a significant influence on transient response. I have built 5 units so far and they all behave the same way.

I'm not saying that anything is broken, I actually kind of like having yet another option available to shape the tone. Just haven't seen it documented anywhere and no mention of it.

The -6 setting (switch in upward position, filters bypassed) sounds slightly more 'in-your-face'. I like the -12 setting (filters bypassed) when going for slightly slower transient response, to move things backwards a bit.

With all the different options available for tone shaping the VP28 quickly turns out to be a Swiss-army-knife kinda device.  8)

I never noticed this, but i'll check on it tmrw and report back, it seems strange that would happen though?

 

[kante1603]

Hmmmm.....I can't remember having noticed anything like that,but haven't done more than vocalese stuff with them.Filters always in at 40 or 80Hz,12dB/octave.
Will monitor this,thanks for the hint.

Best,

Udo.

 

[jsteiger]

I am not so sure about this from a design aspect. There is no circuit change with the -6/-12 switch if both filter push buttons are out. When the toggle is in the -12 position, the signal makes a additional trip onto and around the HPF PCB but only thru closed switch contacts, no components. I don't have a VP28 here to test but really can't imagine a change myself.

 

[kante1603]

From a logical point of view I don't see any sense or cause either.
Mine are at my work place atm.,will run some Moog sounds with attacks set to zero (the fastest envelope generators ever)  as well as key-clicks of an organ sound through it asap,this should clear it up.

Best,

Udo.

 

[kante1603]

So I ran the before mentioned tests.On all my 8 VP28s.Listening chain was MicPre o/ps directly feeding a passive Monitorcontroller.Speakers are non-forgiving Meyersound HD-1s and in the nearfield Neumann KH120As.
Result:Swapping the slope with no Frequency Bottons engaged does not have any audible influence.
One might change transient response when changing the gain structure,but that is related to things like transformer saturation,therefore a different story.
There might be a measurable difference when looking at the switch resistances in the milliohms area,but I don't think it to be audible.

Hope to have helped and still wondering what's going on,

best regards,

Udo.

 

[Terryb]

So, I'm soldering in c7 and c8 with my iron at 750f.
Then I notice what looks like a fuzzy white spider web.  Did I just ruin the capacitor?

http://moodyandbored.tumblr.com/post/53812512491/wtf

 

[Terryb]

And while I'm at it;

C16 and c20
Are 470 microfarad 16 v

Mine don't have a solid band.  Just arrows with minus signs.
I tried looking it up to be sure, but no luck.

I assume the end the negative arrows are pointing to is the cathode?

 

[jsteiger]

I run nearly at 800F and have never had a problem with overheating a cap (or other component). How long did you heat it for? Not sure what the "spiderweb" is that you are speaking of?

On the 470uF BC's, yes, the arrows point to the negative end. The positive end has a groove running around the can.

 

[Terryb]

Only heated it for a few seconds.

I'm using kester "44" and it could just be a flux buildup.
It kinda looks like a small spider egg sack.
I tried posting a photo, but I don't think my dropbox account is sharing nicely.

 

[Marc Duchesne]

Here are mine, those pre's are very nice...  Still have to built those 2 GIX 51X tube pre's to put in.

Thanks Jeff !

 

[Marc Duchesne]

Power supply inside...

 

[cookiesuttle]

hey all, first time posting.  Just finished building 2 and both have the green led light on constantly.  I noticed another user had the same issue.  Anybody know what I'm doing wrong?

 

[.:On The Rock:.]

Hi Guys,
I'm having a blast building my two VP28s. I have one question though:

I was given two 137k ohm resistors and zero 13.7k ohm resistors. One of the 137k resistors is for R10 and the missing 13.7k is for R8. I'm just wondering if this is in fact a mistake because the same mistake was made in both preamps.

Thanks,
Scott.

 

[jsteiger]

Hi Guys,
I'm having a blast building my two VP28s. I have one question though:

I was given two 137k ohm resistors and zero 13.7k ohm resistors. One of the 137k resistors is for R10 and the missing 13.7k is for R8. I'm just wondering if this is in fact a mistake because the same mistake was made in both preamps.

Thanks,
Scott.

Scott we had a few kits go out like this. Long story but shoot me an email and I will get them out in a regular envelope for you. Make sure you tell me how many kits you have like this.

 

[.:On The Rock:.]

Scott we had a few kits go out like this. Long story but shoot me an email and I will get them out in a regular envelope for you. Make sure you tell me how many kits you have like this.

No worries, that's too much trouble. I'll just run out to an electronics store and pick some up. I mean, the resistors will be cheaper than the postage. I'll get back to you if I can't get the exact ones.

 

[cookiesuttle]

ok me again with the green led problem.

I've checked the orientation of the LED itself along with the 4558 opamp and the surrounding 914 diodes.  All is good there.  I tried flipping the orientation of the 4558 for kicks and then nothing would work. 

Both of my units are doing this.  Can anyone think of anything else I can look at?

 

[kante1603]

ok me again with the green led problem.

I've checked the orientation of the LED itself along with the 4558 opamp and the surrounding 914 diodes.  All is good there.  I tried flipping the orientation of the 4558 for kicks and then nothing would work. 

Both of my units are doing this.  Can anyone think of anything else I can look at?

Hello and welcome to the forum.

From your posts I can not see if you have listened to them .
What is attached to the pres,any signal source or cables?
Maybe there already is something entering the input,maybe you have a hum there or so.
Does the led stay the same when you bring the gain fully down?

Best regards,

Udo.

 

[cookiesuttle]

Hey thanks for the reply!  The green led stays on with nothing plugged in and gain down.  It also stays on with a mic plugged in as well. 

I'm using one of the new lindell audio 500 series racks if that makes any difference.  Unfortunately I don't have any other 500 series units to test it with.