anyone have much experience with EHX DMM?

[namahshaman]

I recently bought an EHX deluxe Memory Man (1100) used, and it sounds fairly distorted and gritty. I've read that this may be a result of using the wrong power supply, which could cause permanent damage. Is it possible that this was the case with mine, or does the analog pedal have a much more lo-fi sound than I expected? (I admit it still sounds cool in its own way ) Does anyone know what it sounds like once damaged?

I've tried going online and watching videos, but most of them are with guitar, so it's harder to tell. Perhaps even more helpful, if anyone has any videos or recordings where they use the EHX DMM with a moog, please share. Thanks

I purchased it from a store, so I'd like to send it back soon if there's a problem. Thanks

[ricknboogie]

It should not be distorted or gritty, unless your signal is distorted or gritty. I'd take it back.

[thealien666]

I have the XO version and it uses a 24 volts dc power supply.

Also, with a synthesizer, the input can be overloaded easily. Just lower the "level" knob maybe ?

Also, at maximum delay time, there is a little bit of aliasing present on high frequency content (like a sawtooth waveform from a synth).
Yes, you read right: aliasing. On an analog delay pedal ??? Yes. The bucket brigade of transistors acts like a digital delay, but instead of storing numbers, they store voltages.
If the clock speed of the bucket shift is low, and the low pass filtering slope of the circuit is not abrupt enough, aliasing artifacts might appear on high harmonics signals.

Hope this helps.

EDIT I've just noticed that you wrote that you have the 1100 version. AFAIK that one uses a 9 volts dc PSU and not the usual 24 volts dc psu.

[stiiiiiiive]

Pretty much has been said yet.

Just to be sure: when you say "1100", do you mean the blue DMM with Tap Tempo, or the black&white original one?...

I've got the former and it does not sound especially gritty.

[namahshaman]

Yes stiiiiiiive, the 1100 is the blue one with tap tempo.

Thanks, thealien666, aliasing . . . weird. sadly, I'm pretty sure this isn't user error. I've read the tiny manual and looked around online, seems like a power issue.

Thanks, everyone. If i get time tonight, I'll record a couple samples of it and throw them up here to get a final judgement before I ship it off.

[thealien666]

Aliasing but only at longest delay times (lowest clock frequency), of course.

It could possibly be a failure of the dc/dc converter circuit inside the pedal that raises the power rail for those Panasonic BBD chips, which are working with minimum 15 volts internally.

Underpowering those chips would distort the signal considerably.

[stiiiiiiive]

Alain, what a specialist you are...

Namah, mine is not gritty at all, again. Well, I mean it certainly is a BBD but not a bit crusher of any kind.
You were lucky finding one; where I live, they've become really rare. I got the last one of one of the last shops having some. If you have to ship it back to have it replaced, hurry just in case they have just one more.

[namahshaman]

Finally got off work early enough to throw these examples together. Please listen and tell me if the DMM is supposed to sound like this

http://soundcloud.com/transmute-11/delay-test

[thealien666]

Definitely sounds like underpowered BBD chips (those chips (Panasonic MN3005) have to be powered by at least 15 volts internally to operate properly).
There is a DC/DC converter inside the pedal, to raise the 9 v dc input to that voltage for the BBD chips. That circuit could be defective.Someone might have mistakingly plugged in the regular 24 v dc PSU from a regular DMM in it. That would definitely damage the internal circuit, since the maximum allowed power is 10.5 v dc, as mentioned in EHX documentation for the DMMTT 1100.

Is your PSU putting out 9 V DC ? (just to eliminate the possibility of a defective external PSU)

If so, then I'm afraid you have a defective Memory Man. Even though it's from a store, it was not brand new right ? Do you think it could be covered by some kind of warranty still ?

Best of luck to you...

[thealien666]

This is how my healthy DMM sounds. (maximum delay time in only about 500ms on mine, as opposed to slightly over one full second for the 1100 model)

Maximum delay time setting:Direct sound first, Delay only sound second. Then both mixed 50-50 with blend control, and with moderately long feedback, at different delay times.

http://soundcloud.com/thealien666/dmm-test/s-O0RW0

BTW, for those interested, I've measured the clock frequency driving the BBD chips (analog sampling rate) and it goes from 8 khz at longest delay time, to 112 khz ! Yielding an audio frequency response, according to Nyquist-Shannon sampling theorem, of about 4 khz at maximum delay, to 66 khz at shortest (more realistically 20 khz due to compander circuit frequency response).

[stiiiiiiive]

Namah, mine doesn't sound like yours either. It definitely sound more like Alain's.

I would bring it back to the shop.

[namahshaman]

Ok, thanks for reassuring me, everyone. I was convinced that it didn't sound right, but also considered that my limited experience with analog delays may have been the culprit. Good to see my ears haven't failed me.

Luckily, I contacted the store I ordered it from (it was a b-stock, so still under warranty), and they said they would exchange it for another one. They have 3 left in-stock.

[namahshaman]

of course, I finally break down and splurge on a DMM, and Moog announces their new delay . . . Oh well, guess I'll finally get a live side-by-side comparison

[stiiiiiiive]

I have the DMMTT and the MF-104z: they are different enough to justify having both.





Tell me I'm right.

Tell me it's not bad.

Please.

[thealien666]

I have the DMMTT and the MF-104z: they are different enough to justify having both.





Tell me I'm right.

Tell me it's not bad.

Please.

The 104z can do things that the DMMTT can't. There's a valid justification right there !