Dating Dyna Comp's

In the last two years I have collected 2 MXR Dyna Comp's through various trades. Both look old. Both react quite differently as well when I use them.

The "newer" one sounds a little brighter, but the compression doesn't really kick in until the knobs are around noon.

The older one compress's like son of a gun. I can barely get the right knob past 9 o'clock without noticing the compression.

I was just curious as to how I would date them?

I was just curious as to how I would date them?

Would like to know that too.

I recently bought a used one, block logo, no LED and no adaptor jack so I suppose it's an 80's (?).

If you can get in to see them, the back of the pots should be coded with the manufacture date of the pot. Try here (http://www.sibcorp.com/writehitsongs/vintage_guitar_amps.html) for a brief intro into source-date codes- scroll down the page a bit. Let us know what you find out!

If you can get in to see them, the back of the pots should be coded with the manufacture date of the pot.

I would like to try this, but I'm very clumsy and I'm afraid to break something.
Any hints on how to do it? Or should I ask someone who's more handy than me?

All I know is I've got one from the late 80s that's just like your second one - perfect at 9:00, ridiculously squished anwhere above that.

HI,

It's really not too tough to pull the board up to check the date codes on the pots, see mY FAQ for decoding info.

Earliest Dynas were script MXR logo, '75 - '76 or so.
Mid versions were block logo smooth paint with no LED or Power jack, '77 - 80
Late original MXR pedals had power jack on the side (1/8" plug) and LED, about '81 - '82
Dunlop made reissues just like the late originals in the 90s with hand wired pots and switch.
Current dunlop reissues use board mounted pots and switch.

Have fun!

Then I have one that is a mid version, and one that is a Late orignial.

They sound and work surprisingly different.

Then I have one that is a mid version, and one that is a Late orignial.

They sound and work surprisingly different.

They used some lousy parts in the later years. Any of the original ones made by MXR can be easily modified with true bypass, LED, power jack etc and we also do a script logo mod on them. The script logo mod uses NOS MXR script logo/Ross compressor transistors which we test for noise and match. Have fun!

If you can get in to see them, the back of the pots should be coded with the manufacture date of the pot. Try here (http://www.sibcorp.com/writehitsongs/vintage_guitar_amps.html) for a brief intro into source-date codes- scroll down the page a bit. Let us know what you find out!

The number on the pots of mine says "1378102", so it should be from the second week of 1981 (?)

Earliest Dynas were script MXR logo, '75 - '76 or so.
Mid versions were block logo smooth paint with no LED or Power jack, '77 - 80
Late original MXR pedals had power jack on the side (1/8" plug) and LED, about '81 - '82


This may be strange, but mine has neither a power jack nor a LED. Or could it be a "late mid version" ?

Earliest Dynas were script MXR logo, '75 - '76 or so.
Mid versions were block logo smooth paint with no LED or Power jack, '77 - 80
Late original MXR pedals had power jack on the side (1/8" plug) and LED, about '81 - '82


This may be strange, but mine has neither a power jack nor a LED. Or could it be a "late mid version" ?

Yes, a very early 1981 is the same as the '77-'80 I guess. have fun!

I was just curious as to how I would date them?

Maybe some flowers and a box of chocolates to start with?
:lol: :wink:

It depends on whether it sounds good that day.