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

[Echo North]

Not a problem - attached is the image of the solder joints for the relays (at this location). I'm happy to provide any other pictures that could help as well.

Got to be either a bad relay or something or relay transistor.

Shoot us an email we can send out replacements.

Mike

 

[Jussi De Nys]

Hi! I'm finally building my lola's (2). First one is almost done!
I got to the first testing stage and there's no smoke ( hallelujah! ). The phantom button makes a click when pushed and lights up to a nice blue. The same goes for the Line engage button. The phase invert button does not make a clicking sound/feeling and only lights up when being pushed in , it stops being blue when it loses my touch. It seems to me that this button might be broken or something, it doesn't click like the other two. I can only hope that ( since there's no smoke and everything lights up) this might be a simple mistake, I sadly don't have the "know how". It's my first build, maybe I should have started with a simpler one Hope you can help me out! thanks in advance!
Greetings from Belgium,
Jussi.

 

[Echo North]

Hi! I'm finally building my lola's (2). First one is almost done!
I got to the first testing stage and there's no smoke ( hallelujah! ). The phantom button makes a click when pushed and lights up to a nice blue. The same goes for the Line engage button. The phase invert button does not make a clicking sound/feeling and only lights up when being pushed in , it stops being blue when it loses my touch. It seems to me that this button might be broken or something, it doesn't click like the other two. I can only hope that ( since there's no smoke and everything lights up) this might be a simple mistake, I sadly don't have the "know how". It's my first build, maybe I should have started with a simpler one Hope you can help me out! thanks in advance!
Greetings from Belgium,
Jussi.

Sounds like you just have a bad switch. Send us an email.

Mike

 

[Jussi De Nys]

Hi Mike! okay,  I send you an email on the hairball "get in touch" page.
Thanks

Jussi

 

[tata]

Mike,

would you please give some detailed information about Lola's current draw?
i guess it depends on the buttons / LEDs / relays activated, and the gain, right?

you wrote "130mA max" in the .pdf - but i was able to see 150mA on the positive rail iirc. - i was pushing the preamp/gain really hard..
at "normal" levels and 2 buttons (Line, Polarity) active it draws around 108mA on the positive rail
the negative rail is approx 16mA less than the positive.
DOA1 (990C+) is warmer than DOA2. (both are quite warm)

PSU is a linear type w/317-337s, set to +/-16VDC (+48V)

the overall performance is really great, noisefloor is only 1-2dB higher than what my RME can measure.
(Line In, Gain @ minimum, Output set to unity gain)

do i need to check / fix something, or this sounds OK to you, techincally?

thanks

 

[hellofishy]

Hi!

I just recently built a Lola (this is my first build so needless to say I am not the most precise... However, the Lola mic circuit works great. The phantom power seems to work, etc... However the meter does not work at all.  It does not light up.  I was wondering where I should look to troubleshoot this?  Any help would be greatly appreciated. 

Thanks,
Zack

 

[hellofishy]

Hi!

I just recently built a Lola (this is my first build so needless to say I am not the most precise... However, the Lola mic circuit works great. The phantom power seems to work, etc... However the meter does not work at all.  It does not light up.  I was wondering where I should look to troubleshoot this?  Any help would be greatly appreciated. 

Thanks,
Zack

update: i resoldered some of the points on the IC of the meter and it seems to work! is it normal that the levels on the different meter modes are very different?

My real issue: the DI is  VERY distorted at any high gain level - not the pleasant type of distortion like on the mic and line input.  It sounds like a very bad fuzz that keeps cutting out.  Any idea where I should look on the PCB to fix this?

 

[Echo North]

Mike,

would you please give some detailed information about Lola's current draw?
i guess it depends on the buttons / LEDs / relays activated, and the gain, right?

you wrote "130mA max" in the .pdf - but i was able to see 150mA on the positive rail iirc. - i was pushing the preamp/gain really hard..
at "normal" levels and 2 buttons (Line, Polarity) active it draws around 108mA on the positive rail
the negative rail is approx 16mA less than the positive.
DOA1 (990C+) is warmer than DOA2. (both are quite warm)

PSU is a linear type w/317-337s, set to +/-16VDC (+48V)

the overall performance is really great, noisefloor is only 1-2dB higher than what my RME can measure.
(Line In, Gain @ minimum, Output set to unity gain)

do i need to check / fix something, or this sounds OK to you, techincally?

thanks

Sounds fine.

Most of the current (if not all) is flowing rail to rail not rail to ground.

Mike

 

[Echo North]

update: i resoldered some of the points on the IC of the meter and it seems to work! is it normal that the levels on the different meter modes are very different?

My real issue: the DI is  VERY distorted at any high gain level - not the pleasant type of distortion like on the mic and line input.  It sounds like a very bad fuzz that keeps cutting out.  Any idea where I should look on the PCB to fix this?

Yes they are referenced differently.

Most DI sources are pretty hot for the Lola.  Are you sure you're not clipping something else in your chain? You'll need to roll back on the output once you get into higher gain.

Mike

 

[hellofishy]

Yes they are referenced differently.

Most DI sources are pretty hot for the Lola.  Are you sure you're not clipping something else in your chain? You'll need to roll back on the output once you get into higher gain.

Mike

Hi Mike!

Thanks for the reply.  I don't think it's a gain staging thing as this happens when the meters are only at 1 or 2 LEDs lit up. It's also not pleasant saturation as if I overload the mic or line -its a completely different sound that sounds like the signals is breaking up and cutting in and out rapidly.

 

[Echo North]

Hi Mike!

Thanks for the reply.  I don't think it's a gain staging thing as this happens when the meters are only at 1 or 2 LEDs lit up. It's also not pleasant saturation as if I overload the mic or line -its a completely different sound that sounds like the signals is breaking up and cutting in and out rapidly.

Where is your output control set?

Mike

 

[hellofishy]

Where is your output control set?

Mike

I have tried it set at lowest with the input gain up and I have tried at highest with the input gain down.  The input signal sounds clean up until the VU meters start showing a signal (for the DI)- then it begins to break up.

Also I dont know if this is of importance but I ran the two signals (from the balanced cable) into an oscilloscope and they dont seem to be perfeclty out of phase? instead of 180 degrees seperate it seems more like 140.  I really dont have much idea what I am doing as I am new to this but I thoguht that I would mention that just incase its of importance.

I appreciate all the help

Thank You,
Zack

 

[Echo North]

I have tried it set at lowest with the input gain up and I have tried at highest with the input gain down.  The input signal sounds clean up until the VU meters start showing a signal (for the DI)- then it begins to break up.

Also I dont know if this is of importance but I ran the two signals (from the balanced cable) into an oscilloscope and they dont seem to be perfeclty out of phase? instead of 180 degrees seperate it seems more like 140.  I really dont have much idea what I am doing as I am new to this but I thoguht that I would mention that just incase its of importance.

I appreciate all the help

Thank You,
Zack

Your output should be at the fully clockwise (max setting) for the cleanest output.

Then turn up your gain slowly.

Is only the DI distorting?

 

[kato]

I may have an older revision of the LED board here.
What are good values to use for DR1 - DR10?

I'm guessing newer revisions only have 6 resistors onboard. The build guide says: " Mount the six 47K resistors into DR1-DR6. "

Should I use 47k for all 10 positions?

 

[TillM]

as far as I remember I used 47k resistor from D1 to D10.

 

[hellofishy]

Your output should be at the fully clockwise (max setting) for the cleanest output.

Then turn up your gain slowly.

Is only the DI distorting?

Yup. Only the di. I have tried all gain stage settings and encountered the same problem with a high input signal.  Also I didn't mention that the phase issue was for the microphone input . I don't know if this is related to the di but the microphone balanced output two signals don't seem to align. They are opposite phase but one is slightly shifted

 

[Echo North]

I may have an older revision of the LED board here.
What are good values to use for DR1 - DR10?

I'm guessing newer revisions only have 6 resistors onboard. The build guide says: " Mount the six 47K resistors into DR1-DR6. "

Should I use 47k for all 10 positions?

White LEDs were 10K, orange were 8.2K, and violet was 3.4K.

 

[Echo North]

Yup. Only the di. I have tried all gain stage settings and encountered the same problem with a high input signal.  Also I didn't mention that the phase issue was for the microphone input . I don't know if this is related to the di but the microphone balanced output two signals don't seem to align. They are opposite phase but one is slightly shifted

I would guess the phase issue is something in your test set-up. I think you mentioned you were new to using a scope. I don't think it would be possible o see phase shift like that in the build unless your output transformer was wired incorrectly.

If the mic input sounds fine, I would suspect an issue with you FET Buffers. You can request a new pair on the site if you like.

Mike

 

[shortyboyboy]

Hello! I am at the testing stage of the lola mic pre and am having no luck getting sound. 

The Line, Phase, and +48 buttons light up.  The actual buttons click when I engage and disengage them, but not through my monitors or anything.  When I plugged the instrument 1/4" into the front there was no signal either. I think I may have heard a pop the first time i plugged it in.  Just nothing after that. 

I have checked my signal flow with cables and I should be getting a signal. No smoke is coming from the preamp, and it doesn't look or smell like anything has fried

I'm wondering steps I need to take to figure out what I did wrong here.  I will include pictures that can possibly help you see if I did something wrong.

Thanks so much!  I'm really looking forward to getting this preamp to work.

 

[Potato Cakes]

Do the relays click when you insert the 1/4" cable? Have you tested voltages to the DOA's? Did you build the 990's? have to tested voltages to the IC's and Jfet's? Power is usually the first thing you should check.

Do the LED's on the meter light up when you try to run signal through it? Have you tried adjusting the gain settings? You may have some bad connection with one of the Grayhill pins and or it's resistors.

Thanks!

Paul