[BUILD] Hairball Audio "Lola" Mic Pre - On Sale Now

[dduwa]

Hey guys,

My first build is melting the 10 ohm, R31 and R32 resistors. My first thought is I have a problem with one of the DIY 990's pulling too much current in DOA socket 1.  R36/R37 for socket 2 look to be still in tact.  I've visually gone over each component compared to the other DOA I built, and everything appears to be in the right place.  Q8 and Q9 have the correct transistors and there are no shorts from diodes to the clamp.  Before I swap the suspect DOA into socket 2 to see if it melts R36/R37, is there anything else I should test/verify?  Just for clarification I'm using 16v rails in an API 500 series rack.

-B

I had the same problem with my first DIY990 as well. Ended up building another one and it turned out fine.

As for my PPM issue, it's still a mystery. I cleaned up the flux the back of the board and verified that the value of C106 is 2.2uF and it's oriented properly. Still does the same thing. I'm not too worried about it at this point, since the pre appears to work properly. I appreciate everyone who gave me feedback!

 

[TomZmuda]

Just finished a build of the Lola today! After running all the usual tests, she works like a charm! So much headroom, so clean. I'm very happy!

I was a bit concerned after I finished the audio circuit. Prior to installing the meter circuit, the Grayhill gain pot didn't actually do anything. The Output attenuator was the only control I had over the level of the signal. However, after installing the meter circuit, I had full control over the gain. And of course, I had way more gain available to me than I'll probably ever need!

Kudos to Mike and Hairball Audio for an extremely well put-together kit! I'll surely be ordering another one in the near future!

Tom

 

[shabtek]

they are not finished and ready to go until you test them.

maybe a short or reversed component--are the opamps proven good/can you test them somewhere else?

build an extender or lash up some leads to power the thing and probe voltages

 

[okgb]

you can disconnect the meter board to isolate it somewhat . I had some solder " overflow " on my
meter that was a problem until I corrected it , and as shabtek mentions pop the opamps out to eliminate
that as a problem

 

[theokbird]

Hey there, just built my first Lola and it sounds great!  only problem is that LED 6 wont light, i replaced it 3 times just to rule out a bad LED, as well as checked for any shorts in the area and i still cant get it to light. i searched for any solder bridges or other potential shorts on the meter and LED pcb but to no avail. i know it's installed correctly and the LED works and i dont have a solder bridge on the pcb, any suggestions?

 

[signalflow1176]

Hi, I just finished building the first of my Lolas and everything was checking out fine until I hooked up a 57 and jacked the gain.  When the gain knob is at the notch before 48dB and the T-pad is in the normal fully clockwise position the meter pegs all the way up and there is a lot of noise, and the signal gets quiet and distorted.  If I back off the T-pad it goes back to sounding good, just a lower level of course.  If I hook up any of my condenser mics everything seems just fine, and also the DI seems to be working great too.  Is it possible that the impedance of whatever is feeding the lola is what's causing it?  I have Diy-990s in it and nothing fried, and have been looking for any sort of shorts or misplaced components on the lola board and the op amps, so far everything is checking out correct.  Any hints of what could be causing this would be greatly appreciated!

 

[bruce0]

hooked up a 57 and jacked the gain

Assuming sm57 was connected via xlr not di?

 

[useme2305]

signalflow1176, if you ordered a pair i'd built the remaining two DOA and test them in the first unit to exclude the possibility of a faulty doa.

 

[taliska]

Hi all,

Just building my first lola, and noticed when i was assembling the meter that the resistor bag says:

1 x 723R (R114 labelled 732R on PCB)

which I take to mean that the included part is 723R but has been mislabelled 732R on the board.

However, the colour code for the resistor in the bag is in fact 732R and I've checked with a multimeter and it agrees...(731R)

(and the board is labelled 723R...contradicting the advice!)

Not a big deal, but I think the text on that label needs it's 723 & 732 values swapped! ;-)

Cheers,

Kaz

 

[okgb]

When I did mine , I likely noticed it to be the only one left and made that assumption,
Good catch though!

 

[taliska]

When I did mine , I likely noticed it to be the only one left and made that assumption,
Good catch though!

Yeah, I only noticed it because I was using the labelling on the bag as a guide rather than printing out the sorting sheet...had me worried for all of five seconds!

Anyway, my lola is finished and tested and seems to be working fine. The build itself was very straightforward and super organised, but I have to admit to worrying slightly about the DIY990s...there was enough complexity there that when I got to the end and plugged them in, I had my doubts that they would work...(just because they're the densest DOA I've built so far).

Anyway, thanks Mike for a great build. Only done a few tests, but sounds really nice so far. Pic attached to celebrate!

Cheers,

Kaz

 

[tonycamp]

hey fella's, i'm about to pick up a pair of lola's, and i'm wondering of experiences with it and ribbon mics? The design lends itself to being perfect for ribbons by my noob understanding... The lola sounds exceptional in the samples i've heard thus far.

thanx
T

 

[Conviction]

Hi!

When will the Lola kit get back in stock? I'm eager to order one 
Thanks!

Best,
Olle

 

[withnail]

I'm getting a bit of "scratchiness" when I adjust the Output but only on the DI, as far as I can tell.  It almost sounds like there's some DC across the 600R attenuator.  Any guesses at what this might be, or maybe this is normal?  Otherwise, sounds great!

Also...a question out of ignorance...  In peak metering, the LEDs are fine and I can easily adjust the gain to put into the red (or the violet in this case) but on "VU" mode I only get the first couple white LEDs to light up. I'm not versed in the ways of reading a VU, so is this to be expected?

Thanks!

 

[withnail]

Regarding the issue I posted above, I noticed that it's actually present on both XLR and DI.  So, that disproves my original discounting that it may be a scratchy pot.  Before I go in there and destroy the nice Bourns t-pad attenuator, is there any reason why I should be wary of using Deoxit on one of these?  I wasn't sure whether there were any special considerations since (I think) they are conductive plastic.  Assuming it's okay to use, is the best way to clean it to spray at the base of the shaft (uh...he said "shaft" 8)) and let the solution weep into the pot?

 

[Conviction]

Regarding the issue I posted above, I noticed that it's actually present on both XLR and DI.  So, that disproves my original discounting that it may be a scratchy pot.  Before I go in there and destroy the nice Bourns t-pad attenuator, is there any reason why I should be wary of using Deoxit on one of these?  I wasn't sure whether there were any special considerations since (I think) they are conductive plastic.  Assuming it's okay to use, is the best way to clean it to spray at the base of the shaft (uh...he said "shaft" 8)) and let the solution weep into the pot?

I have not built one of these (yet), but oxidation seems rather unlikely considering it's a new build with fresh components, don't you think?
I'd say make a thorough clean with isoprop alochol and carefully check your solder joints.

 

[okgb]

My output attenuator is  " scratchy " as well  although I haven't dealt with it yet
I don't believe it is possible to clean them .

 

[Echo North]

If it's scratchy, it's most likely poor assembly at the Bourns factory. 

Send us an email.

Mike

 

[Stew9n1]

Hey Mike (or anyone that may know what the issue is), I've built two Lolas and they sound incredible. My friends own a studio and are very happy with them. The second Lola I built though has a strange issue. After a couple weeks of working fine, it now will randomly make a clicking noise that actually shows up on the metering pcb and in ProTools. My friend said because it was random and was showing up on the tracks he had to stop using it for recording. I'm not ruling out that my build was less than perfect, but because it started happening after a few weeks it leads me to believe that something malfunctioned inside the box after time and I'm really not sure where to start. I may end up taking it to a professional, but if anyone has any ideas about what could be causing the click and where I should maybe start to look it would be MUCH appreciated. Thanks!

 

[useme2305]

here's my guess. check for cold solder spots on the relays...maybe just touch them up with a soldering iron and maybe even apply some fresh solder just to be sure.