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

[Echo North]

Check all of that relay circuitry.  Make sure the DI is making good contact with itself when nothing is plugged in.  Clean any tarnish.

If all else fails shoot us an email.

 

[Stew9n1]

Awesome, will the relays and DI asap. Thanks!

 

[Stew9n1]

Just figured I'd throw it on here that re-soldering that circuitry fixed the problem, thanks guys!

 

[Oddio]

I picked up a lola kit and after assembling and passing tests I've noticed a buzzing sound at high gain +60, even without anything pluged in to the input.  Api 512c and avedis ma5 are virtually silent in comparison.  Tried it in api 6b and api 6b-hc (newest version) and a 500vpr with external psu. Is this normal behavior?  I did notice when I touch the gain know the buzz reduces to about 50% but still quite loud.  I would assume this would be a shielding issue?  Any help would be greatly appreciated.

 

[Finter]

Hey all,

Just finished my Lola build, just plugged it in and went to run some tests.


Pushbuttons light up and relays click, and it passes a clean signal, but the meter doesn't show anything and the gain knob doesn't change the signal, but the output knob  appears to function fine. I noticed someone earlier in this thread had a similar problem before they connected the meter board so I imagine my problem lies  there.  The meter does light up a bit when I flip the VU/ppm switch.

Any ideas of what I should check first?

Thanks in advance!

Sean

 

[Echo North]

Hey all,

Just finished my Lola build, just plugged it in and went to run some tests.


Pushbuttons light up and relays click, and it passes a clean signal, but the meter doesn't show anything and the gain knob doesn't change the signal, but the output knob  appears to function fine. I noticed someone earlier in this thread had a similar problem before they connected the meter board so I imagine my problem lies  there.  The meter does light up a bit when I flip the VU/ppm switch.

Any ideas of what I should check first?

Thanks in advance!

Sean

I'd start by getting it working WITHOUT the meter PCB connected.  Seems like you have two issues.  A gain issue and a meter issue, get the gain/pre working right first.

Go through all of the Resistors in the vertical gain R's an mage sure they are in the right place/value.  Is the gain loud or quiet?

Mike

 

[Finter]

I'd start by getting it working WITHOUT the meter PCB connected.  Seems like you have two issues.  A gain issue and a meter issue, get the gain/pre working right first.

Go through all of the Resistors in the vertical gain R's an mage sure they are in the right place/value.  Is the gain loud or quiet?

Mike

Not sure exactly what you mean - it seems fairly quiet but the output knob gets it quite hot. The gain knob changes nothing. Gonna check over the gain resistors when I get a chance.

 

[samguaiana]

Hi there!

I grabbed two Lolas from a seasoned builder who was letting them go. I have a couple questions. First, do DOAs affect headroom? My signal will (pleasantly) distort almost anything after 35. I know there are CAPI 1731s in them. The output gain still has a ton of juice, but then I'm bringing the noise floor up, and its not as clean.

Question two. One of them crackles pretty vigourously when the stepped input pot is switched. It will do nothing for a few clicks, then from 35 on it will start to pop. It will do this on the way down too. Then it will settle. It never does it unless the pot is moved.

I know the builder soldered the top and bottom very cleanly to keep everything nice and in place. And they sound fantastic on overheads. But coming from something like my 512c's that were chalk full of too much headroom, I'm just caught off guard.

Thanks in advance!

 

[Echo North]

Hi there!

I grabbed two Lolas from a seasoned builder who was letting them go. I have a couple questions. First, do DOAs affect headroom? My signal will (pleasantly) distort almost anything after 35. I know there are CAPI 1731s in them. The output gain still has a ton of juice, but then I'm bringing the noise floor up, and its not as clean.

That seems weird.  DOA could definitely change the headroom. 

Question two. One of them crackles pretty vigourously when the stepped input pot is switched. It will do nothing for a few clicks, then from 35 on it will start to pop. It will do this on the way down too. Then it will settle. It never does it unless the pot is moved.

Something sounds off.

I know the builder soldered the top and bottom very cleanly to keep everything nice and in place. And they sound fantastic on overheads. But coming from something like my 512c's that were chalk full of too much headroom, I'm just caught off guard.

Thanks in advance!

You could send it in for a check up if you like.

 

[porkyman]

my lola isnt passing any audio. im not hearing any relays except on power up.  im not a beginner.  this is my 7th diy (actually thought it was the easiest) build but i still consider my self a noob because i dont really know what im doing.  im just a direction follower.  the only thing i can think of trying is replacing the doa's. i only have gar2520's and not sure if its ok to swap them. anyone have any ideas?

 

[Echo North]

my lola isnt passing any audio. im not hearing any relays except on power up.  im not a beginner.  this is my 7th diy (actually thought it was the easiest) build but i still consider my self a noob because i dont really know what im doing.  im just a direction follower.  the only thing i can think of trying is replacing the doa's. i only have gar2520's and not sure if its ok to swap them. anyone have any ideas?

Start with putting the gar doa's in.  No changes needed.  See if that gets it working.

That'll tell us if it's the doa's or main pcb.

Mike

 

[porkyman]

yep. it is one of the amps.

 

[porkyman]

top

 

[Echo North]

Imposible to trouble shoot from photos.  If you can read the schematic, you should try and trace the signal and see where it dies.  Check that the out put transistors are in the right place.

Otherwise you may need to build a new opamp or get a built and tested one.

Mike

 

[porkyman]

where i can i find the schematic. it doesnt look like you sell them diy anymore, is that true.

 

[Echo North]

Opps.  Yes we still do, they're back up:

http://www.hairballaudio.com/shop/index.php?cPath=37

schematic:
http://mnats.net/files/DIY.JE-990.DOA.V1A.pdf

PCB in that doc is different, but schematic is the same.

 

[bulghur]

Hello Mike,

I bought two Lolas at different times and the meter lower white LEDs are different colours -- the older one is more yellow.  What is the mfr part number of the new, cooler (as in colour temperature) white LEDs so that I an order them from Mouser/Digikey, etc.

Thanks,

Bulghur

 

[Echo North]

Hello Mike,

I bought two Lolas at different times and the meter lower white LEDs are different colours -- the older one is more yellow.  What is the mfr part number of the new, cooler (as in colour temperature) white LEDs so that I an order them from Mouser/Digikey, etc.

Thanks,

Bulghur

Ya those vintage yellow ones arrived DOA a lot.

New bright whites are mouser part 593-VAOL-3LWY4

Mike

 

[Echo North]

Hi I have been building a lola mic pre amp and have gotten to the end of the main pcb installation. In the guide it says to test it out so that's exactly what I did. The led lights came on when I pushed the buttons but when I tried to connect a condensor, a 57 and a guitar, none of them worked or showed any signal. I went over all the steps and everything seems to be in place correctly but I did take note of a few things that I saw when I was putting the pcb together. One on the resistors brown and purple seem to be mixed up because when I use the website to calculate the colors purple can never be the last color but if I make it Brown then it adds up perfectly. That is a problem since it is clearly purple but after eliminating all the  other resistors I must assume they either sent the wrong ones or used the wrong paint. Then I also noticed some of the colors that were suppose to have a .01 tolerance, have a 1 % tolerance according to the color code. Lastly I noticed they said to ignore the slots at the top of the board labeled opt c and opt r if you're using jh 990's but mine came with je 990s so I am unsure if that means anything. Any advice helps, appreciate it!

Purple one the last line of a 5-band color code is 0.1% where brown is 1%.

If you received 1% for the 3.4K or 6.8K that is fine.

If you built your own opamps I suspect that first as an issue.  Building those JE-990 is the trickiest part.  Feel free to post some images of you rebuild here and I can at least look it over.  If you have some other opamps like 2520s that you know work try those.

Mike

PS - we also offer a $50 flat fix fee on Lolas/Elements if you get stuck.

 

[porkyman]

i had been using the lola for a few weeks without the meter working and it sounded great. i decide to fix the meter (had the two ic's switched) and now its making this crazy siren noise when i hook it up. like an old ham radio searching for frequency. even without any signal running through. it makes absolutely no sense because i didnt touch the main pcb at all. i even disconnected the meter ribbon and it still does it. 

any ideas