Author Topic: Quasar v3 help?  (Read 1480 times)

spilla

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Quasar v3 help?
« on: September 03, 2021, 11:38:14 PM »
Just finished building the Quasar V3. Had a few issues with the etch but i've added some jumpers and the circuit seems to be 90% working. But i have some issues i would like advice on

1) The drive knob is working counter clockwise. Is this normal? ie i get more gain turning clockwise.

2) if i have the bass knob over 95% the volume drops. Ive replaced the pot and i still have the issue.
 
« Last Edit: September 04, 2021, 09:52:28 PM by spilla »

Zerro

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Re: Quasar v3 help?
« Reply #1 on: September 04, 2021, 10:29:16 AM »
Didn't find no schematic at web. Any picture to offer?
"Nudíte se? Kupte si našeho cvičeného ježka! Pobaví vás svými veselýmí kousky!"

spilla

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Re: Quasar v3 help?
« Reply #2 on: September 04, 2021, 06:12:35 PM »
Didn't find no schematic at web. Any picture to offer?

Its one of madbeans etch layouts, here's a a pic of the schem from the build doc. Cheers!



madbean

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Re: Quasar v3 help?
« Reply #3 on: September 04, 2021, 06:29:45 PM »
1) The gain pot should work as you described - increased gain as it is turned clockwise.
2) The bass pot thing - hard to say. Something could be shorting out in your connection. When its turned fully clockwise (when you say your volume drops), lugs 3 and 2 of the bass pot should read direct connection to R9 and R10 and C4 is fully shorted. So, if you have a continuity checker you might want to verify that setting. And, perhaps do a continuity check against the pot and C5 as well as R11.

spilla

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Re: Quasar v3 help?
« Reply #4 on: September 04, 2021, 09:35:45 PM »
Continuity behaves as expected. I replaced r9, r10, r11, c4, C5 and the bass pot again (just incase i had a bad batch, this time from a different supplier). Ive also reflowed in that area and checked for any bridges.

Would replacing r12 and C7 be worthwhile?

Ive also added another jumper from from c7 to c8 and IC1. Continuity was fine in that area but there was some part of the traces that were removed when etching. (i swear this is the last time i use jumpers, would rather just re-etch. It never works out well for me!)
« Last Edit: September 04, 2021, 10:10:16 PM by spilla »

Zerro

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Re: Quasar v3 help?
« Reply #5 on: September 05, 2021, 04:11:04 AM »
Drive raises as drive pot rises his resistance. Only change pins 1 and 3, (using Linear pot).
"Nudíte se? Kupte si našeho cvičeného ježka! Pobaví vás svými veselýmí kousky!"