Audio Electronic Circuit Schematics

Talk about music gear for noise music

Moderator: xome

User avatar
timdrage
Posts: 5022
Joined: Sun Feb 05, 2006 11:08 am
Contact:

Re: Audio Electronic Circuit Schematics

Post by timdrage » Mon Oct 08, 2018 3:18 am

Yes the one with the mini cartridge. Motor runs fine but the entire cartridge holder, tape heads and the cart itself broken beyond proper fixing, has been badly repaired over the years with wrong screws etc so nothing goes together properly any more. Had it kind of working in a nicely broken sounding way but like I say I think I need to hack some other tape mechanism into it.

User avatar
WhiteWarlock
Posts: 1903
Joined: Tue Apr 10, 2018 7:58 am

Re: Audio Electronic Circuit Schematics

Post by WhiteWarlock » Mon Oct 08, 2018 9:41 am

Image
Image
Image
Do you have this type of "Apollon tape"?
The top problem on those tapes with that unit is the "tape pressure pads"
do you have any squishy foam pads that IC chips are stuck on during shipping?
make replacement pads for keeping tape on tape heads......................
insert under tape in case.......................................
the old pads on those tapes disintegrate over time..................
you can hack something together even if it is simple tape loop in Apollon case
btw felt didn't work as well as IC chip foam
get creative when troubleshooting
best of luck
cheers

silly question time....
can you somehow mount the record/play heads so they make better contact with tape?
sounds like your Univox tape delay unit will function with some creativity from your description IMO

User avatar
WhiteWarlock
Posts: 1903
Joined: Tue Apr 10, 2018 7:58 am

Re: Audio Electronic Circuit Schematics

Post by WhiteWarlock » Mon Oct 08, 2018 3:40 pm

Awesome pedal perf/strip/pcb layout resource site:
http://effectslayouts.blogspot.com/


User avatar
timdrage
Posts: 5022
Joined: Sun Feb 05, 2006 11:08 am
Contact:

Re: Audio Electronic Circuit Schematics

Post by timdrage » Sat Oct 13, 2018 1:30 am

Yep it's a that same kind of cartridge.l, totally broken tho. Ah the IC anti-static sponge idea is a good call. I've fixed 8-tracks before with some kind of window insulation foam tape stuff too
Can you somehow mount the record/play heads so make better contact with tape?
That was the plan but it's broken or loose in so many places that it barely functions :) I did try attaching a walkman temporarily and that seemed like it would work, I should properly rebuild soon that way :)

User avatar
WhiteWarlock
Posts: 1903
Joined: Tue Apr 10, 2018 7:58 am

Re: Audio Electronic Circuit Schematics

Post by WhiteWarlock » Sat Oct 20, 2018 11:55 am

REDACTED
Last edited by WhiteWarlock on Tue Dec 04, 2018 10:41 am, edited 6 times in total.

User avatar
WhiteWarlock
Posts: 1903
Joined: Tue Apr 10, 2018 7:58 am

Re: Audio Electronic Circuit Schematics

Post by WhiteWarlock » Sat Oct 20, 2018 7:05 pm

REDACTED
Last edited by WhiteWarlock on Sun Oct 21, 2018 8:04 pm, edited 1 time in total.

User avatar
WhiteWarlock
Posts: 1903
Joined: Tue Apr 10, 2018 7:58 am

Re: Audio Electronic Circuit Schematics

Post by WhiteWarlock » Sat Oct 20, 2018 7:07 pm

REDACTED
Last edited by WhiteWarlock on Sun Oct 21, 2018 8:04 pm, edited 2 times in total.

User avatar
WhiteWarlock
Posts: 1903
Joined: Tue Apr 10, 2018 7:58 am

Re: Audio Electronic Circuit Schematics

Post by WhiteWarlock » Sat Oct 20, 2018 7:08 pm

On my DR-55, in the bottom left (near the tone pot) there was a little trim-pot
which varied the kick decay, but on my friends there was only a resistor. Later
study of the service manual shows that only early serial number DR-55s have the
trim pot, so if you've a later rev. DR-55 here's the extremely simple way to
modify the bass drum decay..

The resistor is in the lower left of the circuit board (looking from above),
just below the tone control. 'BD' is stencilled on the PCB next to it, and the
resistor is over a little stencilled trim-pot picture. The following ASCII
diagram should help you locate the right resistor.

/-\
l l Tone Pot.
\-/
o
o
o ^
^==/ <<-- Resistor to be replaced.


Simply snip out the resistor, and replace with a horizontal trim-pot of several
K ohm. The trim pot goes between the three holes in the silly ASCII diagram
above, with the wiper terminal attached the middle/rightmost hole. I used a 2.2K
that I had floating around (what? your parts don't levitate like mine? freaky),
and that gave a reasonable control range...

Of course, I hold no responsibility for anything bad happening from this...
Last edited by WhiteWarlock on Sun Oct 21, 2018 8:06 pm, edited 1 time in total.

User avatar
crochambeau
Posts: 2822
Joined: Sat Nov 19, 2005 12:48 pm
Location: earth.
Contact:

Re: Audio Electronic Circuit Schematics

Post by crochambeau » Sat Oct 20, 2018 8:33 pm

I get that you're excited about modifying your DR-55, but does that REALLY warrant posting text grab after text grab from an old mail group?

User avatar
WhiteWarlock
Posts: 1903
Joined: Tue Apr 10, 2018 7:58 am

Re: Audio Electronic Circuit Schematics

Post by WhiteWarlock » Sun Oct 21, 2018 6:43 am


Yes... considering this is an archival thread...
anyone doing web search on DR55 schematics/service manual/mods will find this info
(not that there will be many)
and for some reason my wordpress editor is fuct up right now...
so tried saving accumulated post on my site yet this was far less frustrating
(another thing for doing/solving on the list)
when have extra time will figure WTF and why my wordpress edtor toolbar vanished
and images don't show up plus text is white in the edit window
in the middle of other things at this current moment
needed putting the info somewhere for easy/fast web reference
plus the old hyper real posts are relevant information
it's not as if anyone else is posting schematics/service manual/mod info in this thread recently
it wasn't about as you put it all about being "excited"
more practical reason such as saving info in the middle of working on something...
easy web access in this thread so can review/add info if need be during project
BTW for anyone that is here actually researching DR55 mods...
The 5v phone power supply runs the saved pattern...
yet doesn't seem like it is enough voltage for writing pattern
the loading pattern LED stays on constantly in write mode
making edits doesn't change anything in pattern...
hmmmm
(running some more tests today plus recording the current patterns)
looks like time for digging through suitcases of power supplies for 6v PS
thanks for pretending you actually care :P

User avatar
Sleep Of Ages
Posts: 6074
Joined: Tue Oct 26, 2010 2:55 am
Location: Middle of Fucking Nowhere Jungleland
Contact:

Re: Audio Electronic Circuit Schematics

Post by Sleep Of Ages » Sun Oct 21, 2018 7:45 pm

Crochie the Bandwidth Cop.

User avatar
WhiteWarlock
Posts: 1903
Joined: Tue Apr 10, 2018 7:58 am

Re: Audio Electronic Circuit Schematics

Post by WhiteWarlock » Sun Oct 21, 2018 8:21 pm

REDACTED
Last edited by WhiteWarlock on Tue Dec 04, 2018 10:43 am, edited 1 time in total.


User avatar
crochambeau
Posts: 2822
Joined: Sat Nov 19, 2005 12:48 pm
Location: earth.
Contact:

Re: Audio Electronic Circuit Schematics

Post by crochambeau » Fri Nov 16, 2018 7:16 am

Sleep Of Ages wrote:
Sun Oct 21, 2018 7:45 pm
Crochie the Bandwidth Cop.
It's easy for me to fill that role because I live in the sticks without access to broadband and just opening this thread has become an ordeal. (apologies on my delay in reply, I've been filtering my content as a result of user/bandwidth observations).
timdrage wrote:
Fri Nov 16, 2018 5:17 am




free ebook with some of this guy's schematics http://www.lulu.com/gb/en/shop/ko-tilma ... 38043.html
Thanks for the share, fun stuff to mull over, I want more scream. 1 amp at 30 volts, hahaha, that'll keep your tea warm.

Post Reply

Who is online

Users browsing this forum: No registered users and 6 guests