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

[0rgazm0]

Just throwing in a +1 for these pres. I built 2 as my 1st mic pre builds. Messed up something on the 2nd LED meter, but I have tracked guitars and overheads through these and they sound fucking great.  Definitely adding 2 more when funds allow.

 

[iamnotacowboy]

Just received Lola, and I'm so excited. Quick question about resistor values. I'm populating the main PCB, but resistors R20, R21, and R24 seem to be on the low side. R20, which is rated at 3.3M, is measuring ~1.8M. Also, R21 and R24, which should measure 1M, are coming up  ~450K. I'm not sure if this is within the tolerance (i should be better at math). Perhaps DMMs, or maybe just mine, are less accurate at the higher values? I've double and triple checked, so my readings are correct. Any thoughts or assistance is much appreciated.

Thanks

 

[Echo North]

Just received Lola, and I'm so excited. Quick question about resistor values. I'm populating the main PCB, but resistors R20, R21, and R24 seem to be on the low side. R20, which is rated at 3.3M, is measuring ~1.8M. Also, R21 and R24, which should measure 1M, are coming up  ~450K. I'm not sure if this is within the tolerance (i should be better at math). Perhaps DMMs, or maybe just mine, are less accurate at the higher values? I've double and triple checked, so my readings are correct. Any thoughts or assistance is much appreciated.

Thanks

DMM's put themselves in parallel with resistors when measuring them. So depending on the input R of your meter, at some point measuring high R resistors will be inaccurate.  Those resistors should be fine.

Mike

 

[radtunez]

Hey Mike,

Completed my first Lola build recently, and all is up and running and sounding great, save one hitch: the DI isn't working. I've double-checked my joints on the DI relay as well as the jack, and they all look good. The rest of the Pre is working and sounding great. Lots of gain, metering properly, etc. But rather than give up on the hope of using this sans-DI box, I thought I'd post here and see if you had any ideas for why the DI hasn't kicked in.

Thanks

Ryan

 

[Echo North]

Hey Mike,

Completed my first Lola build recently, and all is up and running and sounding great, save one hitch: the DI isn't working. I've double-checked my joints on the DI relay as well as the jack, and they all look good. The rest of the Pre is working and sounding great. Lots of gain, metering properly, etc. But rather than give up on the hope of using this sans-DI box, I thought I'd post here and see if you had any ideas for why the DI hasn't kicked in.

Thanks

Ryan

Check for any shorts (solder bridges) with the di relay. Check the soldering and component value of R20, R19, Q1, R21->R24, Q2, Q3, C10, and C11.

Look for anything weird. Re-flow joints.

Mike

 

[boris1953]

Mike,
Thanks for the meter board. It's slightly different in calibration from the first one. I'm still not sure which one is correct but they're much closer than the other one was. Be purchasing another pretty soon I think. After a rev D. tho. Thanks again.
Danny

 

[Lowfreq]

I have a quick question about the LEDs on the meter.

Earlier in the thread you said what you were using for the white LEDs, but what about the yellow and red ones?
Are they at the same mcd rating of around 2500mcd?

 

[Echo North]

I think we're using these:
WP710A10ID
WP710A10YD

Mike

 

[bugcheck]

Hi Mike, everyone,

I've completed my Lola build and I think everything is working well.  I just wanted to confirm one detail - is it expected that with an audio source plugged in to the DI jack, that pressing the line switch cuts off the audio output?  I assume that it is, and if I understood the schematic correctly, the relays disconnect the DI and run the balanced in through the line circuit.  Is that correct?  I just wanted to make double sure that everything is working as expected before I order my next one.    Kudos on the kit, instructions, and pre itself - nicely done!

Best,
Gary

 

[Lowfreq]

I think we're using these:
WP710A10ID
WP710A10YD

Mike

Thanks Mike, that's quite the difference in mcd rating. I've got some yellow (2100mcd) and red (1000mcd) in my parts draw 20ma. Can I just sub these in or do I need to change some resistors somewhere.?
I could just go get some standard yellow and red leds closer to the ones you've specified. They just seem to be quite different to the ratings on the white ones.

Steve

 

[lhmusic]

When I plug in an instrument to the DI, turn down the instrument volume knob and crank the gain on the Lola there is a gurgling, cycle noise? Is this normal, does anyone else have this issue?

 

[isp.ben]

Just finished a build on two Lolas. Having different issues with both. One of the units I think has a bad DIY opamp. (that's on me) The other though, has given me the issue of not passing phantom power. Upon first install, the +48V switch would light and then stay lit. Unit would get warm. So I would shut it down. Upon turning it back on the +48V switch would still be illuminated. Thought it was a bad switch, had a new one sent to me. Now the switch appears to operate properly, but +48V is still not being passed through the pre. Thoughts?

Note: Works perfectly with dynamics, ribbons, and the DI. Just not sending phantom. Thanks ahead for anyone's help.

 

[Winetree]

Hey Mike,

Completed my first Lola build recently, and all is up and running and sounding great, save one hitch: the DI isn't working. I've double-checked my joints on the DI relay as well as the jack, and they all look good. The rest of the Pre is working and sounding great. Lots of gain, metering properly, etc. But rather than give up on the hope of using this sans-DI box, I thought I'd post here and see if you had any ideas for why the DI hasn't kicked in.

Thanks




Ryan

Just tried The D.I.s on my 2 Lola builds and having the same problem. They don't work.

 

[pzjones]

Hello Mike. I have just completed building a pair of Lola pre,s and I have one unit that works fine and sounds great. The other unit has a problem with low gain and one of the DOA,s is heating up the 171G. (Very Hot) I have tried a different pair of op amps in this particular unit and it works fine so I guess the problem is in the op amp itself. I have checked the orientation of the 171 and 181 and their diodes and they are good. I have also checked the supply volts to the DOA,s and they are fine also...about 15.6V I have also checked all the solder joints as well as I can and they seem fine. The current supply resistors are all cool. Is it likely to be a faulty Transistor or is there somewhere on the DOA circuit you can point me to that might be the culprit. I assembled these op amps myself. I am usually pretty careful....usually. : Any suggestions.

Many Thanks Paul.

 

[jeroberts]

Hi All --

I'm working through my first Lola build and have come across some problems.  Here goes...

- The pre sounds fine when the Grayhill switch is in certain positions, but sometimes I am getting weird noises that rise and fall in pitch.  Anyone else have this problem?

- The DOAs get really hot within minutes of plugging the pre in.  Is that ok?

- I am not sure I soldered the ground wires correctly.  I have a Lola Rev B and the two holes for ground on the PCB look like they're touching.  Are they supposed to be soldered together?

Thanks!

 

[jeroberts]

Actually ignore the weird noises part.  I was plugging my pre into a 500 series extension card but now that I tried it in the actual rack it's behaving well.

 

[Potato Cakes]

Hello!

I too will give a +1 for these guys. I had a pair of these kits sent out on the road and built them to be used for audience mic recording with MBHO omnis at Red Rocks. Sounds incredible. Even with the crappy Sony headphones I have out here it sounds like something you would experience on a well made 5.1 mix of a great concert. Mostly, it makes me feel like the time I spent climbing trees and taping mics to branches wasn't for nothing.

Thanks!

Paul

 

[mattjhuber]

I am also having issues with the DI of one of my Lolas; it is making this noise: https://soundcloud.com/mattjhuber/lola-noise

This is the 8th Lola I've built, and the first one with any issue. I reflowed solder joints, did a visual check-through...

Any ideas?

 

[achase4u]

I am stunned by the sound of my Gold element pre with Jensen transformers.  Is it possible to use Jensens in the Lola build?

 

[Echo North]

I am stunned by the sound of my Gold element pre with Jensen transformers.  Is it possible to use Jensens in the Lola build?

Sure. You'de have to mount the input on a perf board or something and hand wire it.

Mikr