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

[sir_sig1026]

Hi,

Mike, hoping you read this.  I recently bought one pre-made Lola and then a Kit to build.  So the build went fine, I ran into the common D1/D2 issue (burning resistors) but I know the rest of it works because I have been swapping op-amps between the two.

HERE is my problem (I am hoping you or someone can help because I have scoured the internet for answers). 

First I had 2 API Clones, I was using them in a Radial Workhorse 3-Slot Strip.  Both seemed to have NO low end.  I replaced the Op-Amps, still NO low end.  So I thought maybe it was the rack.  New rack: the Fedenstein Bento2.  Still NO low end.

Fast foward to these Lolas: STILL NO LOW END.  I have a/b tested a note through the preamp and then directly into my interface and there is so much difference.  I am using an Apollo Quad Thunderbolt and going into line-in 1-2, simply bypassing the preamps brings all my low end back.

I have tried 4 preamps, 2 racks and 8 Opamps and still getting no lows, PLEASE HELP!!!  If this can't be solved I am going to have give up on the 500-Series World for now.

 

[TillM]

Did you build the Op-Amps by yourself ?
I think the issue must somewhere in the feedback/gain network section.
Maybe a false resistor, but then you would have 4 faults on every preamp you build.
On the other side, the API clones are simple to build, so then you would have also mistakes.
I would double check all resistors.

 

[Potato Cakes]

Hi,

Mike, hoping you read this.  I recently bought one pre-made Lola and then a Kit to build.  So the build went fine, I ran into the common D1/D2 issue (burning resistors) but I know the rest of it works because I have been swapping op-amps between the two.

HERE is my problem (I am hoping you or someone can help because I have scoured the internet for answers). 

First I had 2 API Clones, I was using them in a Radial Workhorse 3-Slot Strip.  Both seemed to have NO low end.  I replaced the Op-Amps, still NO low end.  So I thought maybe it was the rack.  New rack: the Fedenstein Bento2.  Still NO low end.

Fast foward to these Lolas: STILL NO LOW END.  I have a/b tested a note through the preamp and then directly into my interface and there is so much difference.  I am using an Apollo Quad Thunderbolt and going into line-in 1-2, simply bypassing the preamps brings all my low end back.

I have tried 4 preamps, 2 racks and 8 Opamps and still getting no lows, PLEASE HELP!!!  If this can't be solved I am going to have give up on the 500-Series World for now.

Bad cables?

If the cables are single ended there will be no low end. It's the only thing that seems to be left, especially if one of the Lolas are prebuilt and the interface seems fine.

Thanks!

Paul

 

[TillM]

Good fact Paul!
Maybe the cables a wrong.
I use with my Bento2 Neutrik Stereo jacks to XLR.
The prebuilt Lola should be work without any issues in my opinion, Mike and his Guys know what to do.

Change the cables.

 

[Echo North]

Bad cables?

If the cables are single ended there will be no low end. It's the only thing that seems to be left, especially if one of the Lolas are prebuilt and the interface seems fine.

Thanks!

Paul

Ya I would say it's a cable, patchbay, or interface issue.  Cables are out of phase that can happen.

 

[justin3am]

I realize this is a silly question but...
I have one DIY-990 DOA which is blowing up the 10 ohm resistors around it and in the process of troubleshooting the problem, I have run out of 1% 10ohm resistors. I have a bunch of 5% but I want to make sure that they are safe to use in those spots. Since these resistors are designed to act like fuses to protect the DOA and the surrounding circuitry, I figure it's probably okay, as long as I make sure that the actual value of the resistor is close to 10ohm. Right?
I'm being overly cautious because all my past DIY experience has been with synthesizers, where a mistake wouldn't necessarily be as costly.  ;-)

While I'm at it, it's just one of the two DIY-990s which is causing problems but upon inspection, it appears to be assembled identically to the first. I've tried swapping positions and the problem always follows the DOA. So the problem must be in the DOA itself, right?

Thanks in advance for any guidance.

 

[Echo North]

I realize this is a silly question but...
I have one DIY-990 DOA which is blowing up the 10 ohm resistors around it and in the process of troubleshooting the problem, I have run out of 1% 10ohm resistors. I have a bunch of 5% but I want to make sure that they are safe to use in those spots. Since these resistors are designed to act like fuses to protect the DOA and the surrounding circuitry, I figure it's probably okay, as long as I make sure that the actual value of the resistor is close to 10ohm. Right?
I'm being overly cautious because all my past DIY experience has been with synthesizers, where a mistake wouldn't necessarily be as costly.  ;-)

While I'm at it, it's just one of the two DIY-990s which is causing problems but upon inspection, it appears to be assembled identically to the first. I've tried swapping positions and the problem always follows the DOA. So the problem must be in the DOA itself, right?

Thanks in advance for any guidance.

5% would be fine.

Yes you need to check the diode's clipped to the output transistors on the DOAs.  Make sure the transistors are not swapped or the diodes are not broken/reversed.

Mike

 

[justin3am]

5% would be fine.

Yes you need to check the diode's clipped to the output transistors on the DOAs.  Make sure the transistors are not swapped or the diodes are not broken/reversed.

Mike

:blush: Yeah, I had the output transistors swapped. Works perfectly now. Thanks again.

- Justin

 

[seanweaverguitar]

Forgive me if this has already been asked and is elsewhere in the thread. Just put my Lola build into the rack after returning home and a solid month of delay. (1) As noticed after the build, when I power it on and off in the Neve (R6), there's a fraction of a second spike: the meter jumps to the top and comes back down. This also happens with a really cheap channel strip I did not build at all and need to get rid of,  so maybe this is normal with powering up outboard gear (haven't tried the Pendulum yet; as I've reluctantly expanded from guitar player to self-engineer, so I have some nice gear but am still getting used to using it in a recording environment/what it should & and should not do) and I just keep monitors muted when powering on gear anyhow but wanted to confirm this is normal. If not, I'll go back to the drawing board.

(2) To my relief, it works with condenser mics too (all I had was a 58 to audition it with during the build with my Dad). Everything sounds right. That said, when I push the phantom power switch, there's the same kind of spike and immediate decline thru the VU meter (in other words it happens once and is over).

If it shouldn't be doing that & any of this sounds concerning, let me know. Otherwise I'll follow my usual protocol for power up/down. (I used it all day recording guitars and it's unbelievably great. For the first time in the home studio, the sound is making it from the '63 AC30 onto the recording as the guitar sound should be, which is allowing me to just focus on the playing without fighting the weak links (as OCD as I am about my guitar tones)

Many thanks again,

Sean

 

[Echo North]

Forgive me if this has already been asked and is elsewhere in the thread. Just put my Lola build into the rack after returning home and a solid month of delay. (1) As noticed after the build, when I power it on and off in the Neve (R6), there's a fraction of a second spike: the meter jumps to the top and comes back down. This also happens with a really cheap channel strip I did not build at all and need to get rid of,  so maybe this is normal with powering up outboard gear (haven't tried the Pendulum yet; as I've reluctantly expanded from guitar player to self-engineer, so I have some nice gear but am still getting used to using it in a recording environment/what it should & and should not do) and I just keep monitors muted when powering on gear anyhow but wanted to confirm this is normal. If not, I'll go back to the drawing board.

(2) To my relief, it works with condenser mics too (all I had was a 58 to audition it with during the build with my Dad). Everything sounds right. That said, when I push the phantom power switch, there's the same kind of spike and immediate decline thru the VU meter (in other words it happens once and is over).

If it shouldn't be doing that & any of this sounds concerning, let me know. Otherwise I'll follow my usual protocol for power up/down. (I used it all day recording guitars and it's unbelievably great. For the first time in the home studio, the sound is making it from the '63 AC30 onto the recording as the guitar sound should be, which is allowing me to just focus on the playing without fighting the weak links (as OCD as I am about my guitar tones)

Many thanks again,

Sean

That all sounds normal.  Just that circuits (main and +48VDC) in rushing with current.

Mike

 

[seanweaverguitar]

That all sounds normal.  Just that circuits (main and +48VDC) in rushing with current.

Mike

Thanks Mike. Appreciate you taking the time to answer. Best, Sean

 

[seanweaverguitar]

Posting this with some trepidation to hopefully not make an idiot of myself.....the Lola's sounding wonderful. I just really want to learn more how this stuff works and have become consumed....

I've been looking at the Lola schematic for the past two months and still am missing how the mic level signal gets stepped-up. As I was working on the build with the manual, I looked for how the Line switch triggers K1&2 to flip the primary & secondary and can see that clearly. But for the life of me --- for two months --- I'm not grasping how the mic-in gets to the primary of T1 to be stepped-up. I'm reading it beginning at IN-Hi and IN-LO, tracing the path, and just don't see how the circuit is completed with 8-9 and 2-3 of the relays as drawn. Granted this is all still new to me so I may just be in over my head but after two months had to make the post here (curiosity and sleeplessness was becoming too much)

Hopefully that's kosher to ask and if not, just tell me so. I understand more than I wish about how the world tries to get something for nothing and am not looking to do the same here (just recently I was contacted first for some video instruction; provided my rates & policies, and then was promptly told all they needed was the custom guitar transcription and could I please send that for free...for obscure vintage Chet Atkins stuff unpublished anywhere....which what meager reputation I have as a player & educator is founded on....I only gave a life to the guitar so that really rubbed me the wrong way; plus if I give away stuff for free how am I gonna order more Lola's and Rev As + Ds!!! . So I'd be remiss to come across even close to that. Clearly there's something basic about electronics & reading schematics that I'm missing. But I'm not looking for a hand-out answer (i.e. the free guitar transcription). Even any general suggestions about how to start learning way earlier back at the basics would be appreciated. I'm good at patience (and better at borderline obsession) and working for a goal. Maybe I just need to take a course or few. Right now though I just have no idea where to start and am lost by that in particular, looking over this late into the night; night after night, as March begins...and wanted to start here since it is the official Lola thread after all)

 

[Echo North]

K1 and K2 are in normal mode (unpowered), which is with the transformer set in a tradition Primary->Secondary configuration.

K4, the DI/Mic switch is drawn in it's normal unpowered mode, however once the unit is powered, and there is no DI Jack inserted, the circuit completes and the K4 switches on (up). That completes the path to the primary for the Mic Input.

When you insert a 1/8" instrument into the DI, the relay turns off and returns to the state as it appears on the schem.

Mike

 

[seanweaverguitar]

Thank you Mike. That clarifies a lot and makes perfect sense now. I appreciate you taking the time

 

[TillM]

Swap the op-amps with the good one. See if the issue follows the op-amps or stays in the same unit.

late reply, but I want to help anybody who make the same mistake.
The fault was the LED cable, I did not push it correctly into the terminal, there was a bit space between the pins.
Now everything works as it should.

 

[stephan.gueguen]

Hey there, I recently built a Lola and have had some issues with the DI input.  I was originally shipped some malfunctioning FET transformers, which was causing a sort of DC offset.  Since replacing the FET transformers, I have noticed that the DI input now has an incredible amount of self noise.  The waveform is no longer visually offset as before with the FET issue, but now there seems to be an excess of signal noise.  It doesn't appear to be a ground issue, 60hz hum, its more of a pulsating sound. The line in and xlr in are clean.  The DI Signal, besides the noise, is fantastic. HUGE! Any thoughts on a cause of the problem?  The unit is racked into a Neve R6

Thanks

 

[Echo North]

Hey there, I recently built a Lola and have had some issues with the DI input.  I was originally shipped some malfunctioning FET transformers, which was causing a sort of DC offset.  Since replacing the FET transformers, I have noticed that the DI input now has an incredible amount of self noise.  The waveform is no longer visually offset as before with the FET issue, but now there seems to be an excess of signal noise.  It doesn't appear to be a ground issue, 60hz hum, its more of a pulsating sound. The line in and xlr in are clean.  The DI Signal, besides the noise, is fantastic. HUGE! Any thoughts on a cause of the problem?  The unit is racked into a Neve R6

Thanks

The FETs are actually transistors rather than transformers.

Hard to say, you could certainly try new FETs. The 5457s can be a little problematic if they are outside of the extreme.  We could send you those.

What are you plugging into the DI? You don't have the line in engaged correct?

Mike

 

[stephan.gueguen]

No line in engaged, I have been plugging in two acoustics, with the same noisy result. One is a K&K Pickup, the other is a Taylor stock pickup. Don’t think that’s the cause, as I have put a Radial DI in the chain and run into the mic level input and it sound just fine. Since it’s racked, it is difficult to get to the back, I’d love to have the DI working 100%!

 

[Echo North]

No line in engaged, I have been plugging in two acoustics, with the same noisy result. One is a K&K Pickup, the other is a Taylor stock pickup. Don’t think that’s the cause, as I have put a Radial DI in the chain and run into the mic level input and it sound just fine. Since it’s racked, it is difficult to get to the back, I’d love to have the DI working 100%!

I would try one more set of FETs.  Email us.

 

[frenkonio]

Built a Lola today with two 990. It's the forth I am building and seems the first to have issues. First problem is in the Grayhill. It seems to have a very small amount of gain from ccw to cw (this in LINE mode). In MIC mode is unusable, with phantom engaged you have to put the gain at maximum and output too to have just a couple of white leds moving.
Other issue in the DI section: completely no sound. Where could I begin for troubleshooting? Thanks.