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

[dopelganger]

Hi Mike,

I recently purchased 2 pre built lola pre's with the BA512 op amps.  One of them worked fine, however when I plugged the 2nd one in it seems to be distorting a lot and requires a lot of signal to meter.  There is also a lot of RF coming from the unit.  I tried swapping slots in the Lunchbox but the same thing occured.

any suggestions?  Should I send it back for repair?

thanks in advance!

 

[Echo North]

Hi Mike,

I recently purchased 2 pre built lola pre's with the BA512 op amps.  One of them worked fine, however when I plugged the 2nd one in it seems to be distorting a lot and requires a lot of signal to meter.  There is also a lot of RF coming from the unit.  I tried swapping slots in the Lunchbox but the same thing occured.

any suggestions?  Should I send it back for repair?

thanks in advance!

Try swapping the op-amps.  See if it's the pre or the op-amp.

Mike

 

[dopelganger]

Ok.  I swapped the op amps with a pair of the John Hardy 990s.  They sound fine with the other op amps.

I have some audio clips I could send if that would help. 

The problematic op amps are the BA512s.

 

[Echo North]

Ok.  I swapped the op amps with a pair of the John Hardy 990s.  They sound fine with the other op amps.

I have some audio clips I could send if that would help. 

The problematic op amps are the BA512s.

No sound files, they never help.

Likely, you only have one bad op-amp.  Pop one of your BA512's in there with a Hardy then test. Swap out your BA512 for the other BA512 and test again.  That should tell you which op-amp is bad.  Then email us to get a replacement.

Mike

 

[dopelganger]

I just swapped out 1 of the BA512s with a hardy, and when I took it out to try the other op amp, one of the resistors burnt out      Its the one labeled R32.  It is black and smells burnt. 

Now no signal passes through the unit at all.

 

[Echo North]

I just swapped out 1 of the BA512s with a hardy, and when I took it out to try the other op amp, one of the resistors burnt out      Its the one labeled R32.  It is black and smells burnt. 

Now no signal passes through the unit at all.

Which op-amp is in "DOA1"?

That one is bad.

Mike

 

[dopelganger]

ok.  Whats the procedure for sending it back?

 

[dopelganger]

also...

what about the bad resistor?

 

[Echo North]

also...

what about the bad resistor?

The resistor is basically there to act as a fuse. If the op-amp is bad it sacrifices itself to save the rest of the circuit from damage. That resistor is a hero. I'm not going to tell you what to do with it, but I would bury it in my yard.

Email us "info (at) hairballaudio.com".  We'll get you a new op-amp and resistor.

Mike

 

[dopelganger]

ha!

ok great!

thanks

 

[joshclark]

I have 4 lolas, and one has a fault which makes it about 2-3dB hotter than the others on the output, and the attenuator has very little effect (about -3dB over the entire range of the attenuator).

Has anyone else encountered this problem? I've eliminated the DOAs and the lunchbox slot.

 

[Echo North]

I have 4 lolas, and one has a fault which makes it about 2-3dB hotter than the others on the output, and the attenuator has very little effect (about -3dB over the entire range of the attenuator).

Has anyone else encountered this problem? I've eliminated the DOAs and the lunchbox slot.

Maybe a bad T-Pad?

Also check the feed back resistors and caps.

You could send it in for repair ($50), or order a new pad (you'll have to do it over email) and if that fixes it, we'll refund the t-pad.

Mike

 

[joshclark]

Maybe a bad T-Pad?

Also check the feed back resistors and caps.

You could send it in for repair ($50), or order a new pad (you'll have to do it over email) and if that fixes it, we'll refund the t-pad.

Mike

Thanks Mike, in which case I'll start by swapping out a known working T-Pad first, and work from there.

 

[ehulslander]

Hi Mike

I'm not sure why it's not going through, but I haven't received an email with the repair address.  It doesn't appear to be going to junk either.  I tried to DM you, but it looks like that is closed off.

Is there a different way that I can get the address?  Or to make sure that the correct address is on file?

Erik

 

[Echo North]

Hi Mike

I'm not sure why it's not going through, but I haven't received an email with the repair address.  It doesn't appear to be going to junk either.  I tried to DM you, but it looks like that is closed off.

Is there a different way that I can get the address?  Or to make sure that the correct address is on file?

Erik

I'll send to your email from my gmail.

Mike

 

[seanweaverguitar]

Thanks for a great kit, Mike. I'm building the Lola with my Dad in Olympia. On the Meter Board, R114 and R115 are so close together that neither of us can tell for sure if the solder that flowed through is joining between the two pads.

I invested in a Fluke today (went in for the 177 as recommended but walked out with a 179). We don't really think there's a bridge but it's so small it's a near-microscopic to tell & he can put it under a dental microscope tomorrow to confirm & cut it away with tiny dental tools (he's a dentist) if there is any bridge, but I think it's that the pads themselves are so close together on a packed PCB. I tested with the Fluke & between R114 & R115 it does pass continuity, but looking at the schematic, I don't know enough about electronics yet but it looks like maybe those are supposed to if the those resistors are in series?

Any advice you have would be appreciated. We're getting a microfiber cloth to clean the PCBs tomorrow so I haven't tested anything yet but we're getting close and I didn't want to short something out on the Meter board if that's concerning to you.

Has anyone else run into this on their builds?

 

[Echo North]

Thanks for a great kit, Mike. I'm building the Lola with my Dad in Olympia. On the Meter Board, R114 and R115 are so close together that neither of us can tell for sure if the solder that flowed through is joining between the two pads.

I invested in a Fluke today (went in for the 177 as recommended but walked out with a 179). We don't really think there's a bridge but it's so small it's a near-microscopic to tell & he can put it under a dental microscope tomorrow to confirm & cut it away with tiny dental tools (he's a dentist) if there is any bridge, but I think it's that the pads themselves are so close together on a packed PCB. I tested with the Fluke & between R114 & R115 it does pass continuity, but looking at the schematic, I don't know enough about electronics yet but it looks like maybe those are supposed to if the those resistors are in series?

Any advice you have would be appreciated. We're getting a microfiber cloth to clean the PCBs tomorrow so I haven't tested anything yet but we're getting close and I didn't want to short something out on the Meter board if that's concerning to you.

Has anyone else run into this on their builds?

I like cleaning the bottom with a tooth brush and isopropyl alcohol. Be rough, let it run off.

Yes 114 and 115 are connected on one side.

Mike

 

[seanweaverguitar]

I like cleaning the bottom with a tooth brush and isopropyl alcohol. Be rough, let it run off.

Yes 114 and 115 are connected on one side.

Mike

Thank you Mike.  I'll heed the advice. I appreciate you taking the time to answer these questions.

 

[artifactaudio]

Hey ya’ll!

I build two Lola’s about a year ago, and both served me well in my mobile rig. Despite moving around, they’ve always sounded incredible, until my last session when I realized one of them suddenly is missing a great deal of low end. It’s not entirely filtered out but greatly attenuated.

Bad Cap? Something dead in the op amp? I couldn’t see anything visbibly wrong, so I’m stumped!

Much thanks~

 

[Echo North]

Hey ya’ll!

I build two Lola’s about a year ago, and both served me well in my mobile rig. Despite moving around, they’ve always sounded incredible, until my last session when I realized one of them suddenly is missing a great deal of low end. It’s not entirely filtered out but greatly attenuated.

Bad Cap? Something dead in the op amp? I couldn’t see anything visbibly wrong, so I’m stumped!

Much thanks~

Have you tried swapping the op-amps between the units? See if the issue follows the op-amps or stays with the unit.

If it follows the op-amps, you should be able to swap around op-amps until you identify the bad op-amp.

Mike