Hairball Audio

Re: [BUILD] Hairball Audio "Lola" Mic Pre - On Sale Now
« Reply #440 on: November 02, 2018, 12:28:47 AM »
Hi Mike... I assembled my Lola Mic Pre kit w/ the 990 opamps.  The basic unit works fine except for the last 2 steps on the grayhill... they seem to be highly distorted regardless of output level on the attenuator. This is regardless of Mic or DI input. 

Also the metering does not work at all...   Nothing feels warm in the circuit.  I have a power supply on order since I cannot test anything when its inside of my API Lunchbox thing. 



Sure your not clipping the signal or your converters?

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Re: [BUILD] Hairball Audio "Lola" Mic Pre - On Sale Now
« Reply #441 on: November 25, 2018, 09:42:59 PM »
Hey Mike,

I'm plugging along here assembling my Lola and have noticed that the 4x opamp power supply caps in my kit at bi polar (47uf 25v).  Is this OK or do they need to be polarized? 




Re: [BUILD] Hairball Audio "Lola" Mic Pre - On Sale Now
« Reply #442 on: December 28, 2018, 09:14:49 AM »
Hey guys,

I'm having problems with one of my 990-DIY - I'm smoking the 36 & 37 resistors and I can't seem to figure out what the problem is.

In the beginning I made the mistake that I had the polarity of the diodes on the TO-220 wrong - I put in new diodes and resistors (36 & 37) now but could i have maybe smoked the transistors and that's why the resistors keep smoking?

I've checked the 990 several times now, comparing it with the second one wich doesn't seem to make any problems but i can't find an error or any shorts on the backside..

Do you have any suggestions on what to check?



Re: [BUILD] Hairball Audio "Lola" Mic Pre - On Sale Now
« Reply #443 on: January 01, 2019, 10:19:48 PM »
Completed build smoked r36. Purchased and built another op amp and installed with new resitor, r36. No smoke. Finished assembly all seems good, 3 buttons light up nicely.  Get sound when gain is maxed. Heavy distortion and no led's. Any thoughts?
Thank you.


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