DM-Deluxe Analog Delay

ABE'S CUSTOM EFFECTS

DM-Deluxe Analog Delay

My favorite type of delay is the analog delay.  Many will agree that Electro-Harmonix Deluxe Memory Man or Boss DM-2 gets an instant recognition for the best sounding analog delay pedals out there.

I already own a 1981, Made in Japan, Boss DM-2 with MN3005 BBD chip.  It sounds gorgeous, warm, and lush.  The only draw back for DM-2 is the limited delay time which is about 330ms and I wanted few more modern features such as tap tempo.  So I decided to build my own analog delay pedal.

First, these are what I wanted out of my analog delay: use two MN3005 BBD chips to produce about 550ms of delay time (just like EHX Deluxe Memory Man), ability to add modulation to the delayed signal, a tap tempo (plus sub-division tempos), and instant oscillation switch.  Also run the circuit on 15V to fully utilize the MN3005 chips to its maximum potential.

Here is the explanation of what each control does:

- The knobs (repeat, mix, delay) are self-explanatory so I won't bother.  The rate and depth knobs are for the modulation effect.  The modulation only affects the delayed signal and could be subtle or wacky depending on how you set the knobs.  When the modulation is set right, this could easily substitute dedicated chorus pedal.

- FB limiter:  when this is ON, it limits the feedback volume to a reasonable level.  Analog delays become notoriously loud when you crank the repeat knob as it self-oscillates.  You get this crazy oscillation going but at the same time, you are about to blow your speakers.  This switch just keeps everything under control.  The volume stays near unity level and you get all the crazy oscillation goodness.  Even when you are not using it for keeping the repeat volume down, it darkens the delayed signal which makes it sounds even more analog :)

- Sub-division:  this switch allows me to do dotted eight note runs and do U2-like riffs.  I haven't found the use for eighth note triplets but included just in case.

- Bypass:  I wired it as True Bypass.  I run this pedal through the effects loop of my tube amp and the loop is tube buffered so I don't need any additional buffering when bypassed.

- Slam:  when this momentary switch is pressed, it acts as repeat knob on max, therefore, gives you an instant oscillation.  In conjunction with the fb limiter, it's so easy to make some noise :)

- Tap:  tap tempo with LED that blinks in time.  By the way, I had to put a giant heat sink on the voltage regulator for the tap controller because it was putting off way too much heat and seemed lethal to all of the components around the voltage regulator.  It was basically over working itself to reduce 12V down to 3.3V.  The heat sink end up taking all the heat off of the regulator and the pedal  runs very cool now.

So how does it sound?  Pure analog goodness!!!  It turned out better than what I thought it would be. Now I could safely put away the Boss and rock on with my custom analog delay pedal!

The delay circuit is pretty much identical to Boss DM-2.  However, since I'm running it on 15V, it has more headroom and the delayed signal is running cleaner than the stock DM-2.  So it sounds like super luxurious DM-2, with the functionality of Deluxe Memory Man, with modern updates such as tap tempo and sub-division, and cool slam footswitch that you don't normally see on delay pedals.

This is my first time using the UV printing service.  It looks very professional and although there's that extra cost, I'm glad I did it.  The pedal actually looks a lot more expensive in person.  The camera just couldn't capture the beauty (I think it's my poor lighting).  I also installed purple LED and Boss style knobs to accent its DM-2 heritage.

I had a hard time deciding what to name the pedal but I think the name DM-Deluxe is appropriate since it's highly "deluxed" version of DM-2.