Bass Micro Synthesizer help!

eshears · #1 08-30-2007, 09:59 AM

I just picked up an EH Bass MicroSynth off of eBay. When I plugged it in, there was a significant volume drop (either bypassed or effected), and it didn't seem like the filter or Attack Delay were triggering. When I finally slapped my bass, I could hear just the faintest amount of the filter section.

I'm hoping all I have to do is increase the "Preamp Gain Adjustment". There's just one problem: the "access port" mentioned in the online manual isn't there! So I popped it open, and I found 2 trim-pots in the general area of where the preamp gain adjustment should, but I don't know which one it is. Here's a pic:

Can anyone tell me which (if either) of these trim-pots is the gain adjusmtent? And since there's 2, what does the other one do?

Thanks!

markjazzbassist · #2 08-30-2007, 10:24 AM

Quote:

Originally Posted by eshears

When I plugged it in, there was a significant volume drop (either bypassed or effected), and it didn't seem like the filter or Attack Delay were triggering.

That's cause there's no True Bypass. You either gotta get it modded (I did when I had mine) or learn to live with the tone Suck. That's one caveat about the BMS.

MakiSupaStar · #3 08-30-2007, 10:33 AM

hmmm. I have one of these and I don't get tone suck. I wonder if it's been modded.

sonicvi · #4 08-30-2007, 10:38 AM

The gain adjust is the one on the upper left in the pic. The other one adjusts the gate release of the upper octave.

If the gain pot is properly set you shouldn't really get tone suck. The only problem is you can't compare your bass level to the gain adjust level because it works in active and bypass modes. Converting to true bypass remedies that and is not too difficult.

JanusZarate · #5 08-30-2007, 10:46 AM

Wait... sonicvi, you sure that's right?

I could've sworn the hole would go over the bottom-right trimpot... I'll double-check mine when I get home.

I always wondered what the other pot was for, though! Thanks for the info.

Higgie · #6 08-30-2007, 11:33 AM

I thought it was the upper left one aswell...Though it's been ages since I had my Micro Synth, and I never had to adjust mine, so I've only got a vague idea of where it used to be.

eshears · #7 08-30-2007, 11:53 AM

Quote:

Originally Posted by markjazzbassist

That's cause there's no True Bypass. You either gotta get it modded (I did when I had mine) or learn to live with the tone Suck. That's one caveat about the BMS.

This is not a case of a little tone suck...the volume when connected to the pedal was less than half of what is was plugged straight into the amp! I originally didn't think the pedal worked at all until I turned up to what would be normally a moderate level, and then I could just barely hear it.

Quote:

Originally Posted by MysticBoo

I'll double-check mine when I get home.

Thanks, MB...I appreciate that. I'm really hoping I didn't get a bum pedal.

JanusZarate · #8 08-30-2007, 11:57 AM

Quote:

Originally Posted by eshears

This is not a case of a little tone suck...the volume when connected to the pedal was less than half of what is was plugged straight into the amp! I originally didn't think the pedal worked at all until I turned up to what would be normally a moderate level, and then I could just barely hear it.

That is a possibility if you don't have the gain pot set right. But even when it IS set properly, there will be some minor volume loss. In my setup, it's nothing serious at all (I'm lugging around a 1080W amp

), but a true bypass mod takes the gain circuit out of the bypass and probably be a benefit to you.

markjazzbassist · #9 08-30-2007, 01:32 PM

Quote:

Originally Posted by eshears

This is not a case of a little tone suck...the volume when connected to the pedal was less than half of what is was plugged straight into the amp! I originally didn't think the pedal worked at all until I turned up to what would be normally a moderate level, and then I could just barely hear it.

dude same thing with the one i used to own. i had the preamp maxed bro, trust me, it still sucked tone. i used an active bass with it too, still didn't help. Got it modded, and eliminated the problem.

eshears · #10 08-30-2007, 05:03 PM

I've got a Barge loop/blend pedal on the way, so I'm not too concerned about the tone suck issue...but I actually have to get the thing to work first to see if I even plan to keep it.

Like I said before, right now I get little to no effect from the Attack Delay or Envelope parts of the BMS, although the octaves and square wave seem to be working OK (albeit, very quietly). This is my main concern...

JanusZarate · #11 08-30-2007, 05:22 PM

The envelope section is dependent on the Trigger slider setting combined with the input gain. Once the gain is set, increase the trigger until the envelope kicks in.

However... one part of the envelope section should work regardless of the trigger: the Stop Frequency slider. As you decrease it, the highs will be noitceably rolled off. You won't need to move it much to hear a difference.

Same with Attack Delay... it works regardless of the trigger. It should be audibly working, especially at extreme settings.

JanusZarate · #12 08-31-2007, 01:25 AM

Okay, sonicvi is right - it's that upper-left one.

...I admit defeat.

eshears · #13 08-31-2007, 06:56 PM

Quote:

Originally Posted by MysticBoo

...I admit defeat.

Dun dun duuuuuunnnnn!!!!!

JanusZarate · #14 09-02-2007, 08:21 PM

Quote:

Originally Posted by eshears

Dun dun duuuuuunnnnn!!!!!

eshears · #15 09-02-2007, 08:49 PM

OK, thanks everybody...I got the MicroSynth working much better now. I wonder, though, if it's changed somewhat recently since mine doesn't have the access port. Also, I had to turn the trim pot in the opposite direction of what the manual said.

niftydog · #16 09-02-2007, 11:01 PM

There's several slight variations throughout the decades, yes!

Clockwise vs. anticlockwise is only relevant when you're given a reference point - and you're NEVER given a reference point! Like "clockwise when looking at the bottom of the pedal."