Roland DC-30 Story...

sweetbeats

Reel deep thoughts...
A little vignette...

The Roland DC-30 is an analog chorus/echo box made in the 80's. I've had mine since the early 90's. I picked it up shortly after the reggae band I was in for years broke up. I hated reggae music before I was in the band. They only asked me to join because their drummer at the time was, according to the leader, flakey, and I could play reasonably well. Reggae became and remains one of my favorite styles today, especially classic roots dub...hence why I picked up the analog echo. I also had a Boss RX-100 spring reverb. I wanted to record my own dub music.

Here is a 160kbit wma sample of one of those early ideas from about 15 years ago. Please, do me a favor and ignore the playing...I was just learning how to play bass and also figuring out how to record drums and had only been playing them a few years anyway. I link it here so you can hear the DC-30 in action (as well as the RX-100). IIRC the drums were tracked direct to a Sony TCD-D7 portable DAT through an ART Phantom 1608 mixer, and then the stereo drum track was dumped to a Teac 3340S and from there I laid the bass tracks on tracks 3 and 4 and then mastered back to the DAT through the ART board with the Roland and Boss boxes patched in. Transfer to PC was done 7 or 8 years ago I think via S/PDIF through a borrowed Sony DAT deck and a Digidesign AudioMedia III card. It took a bit to remember this but it makes sense to me now because at first I was trying to figure out why the hi-hat sounded so nice (to my ears) as all I could recall was tracking to the TCD-D7, which had a really thin and harsh quality to it...its that 3340S...still one of the best-sounding recorders I've ever owned (though there may be a deck or two I'll like better in my pile-o-projects). :p

The DC-30 is, in my estimation, a poor-man's Space Echo. It is not a tape-based device.

Here is the Owner's Manual for those interested in such things. I got it off the Roland site awhile ago so it is a public domain freebie AFAIC.

Anyway, I never cleaned up the DC-30 which is unusual for me. I just plugged it in and used it...wierd, huh? :rolleyes:

It was always a pretty tired looking box even from the time I got it...clearly had spent time on the road and likely on the top of a guitar amp...lots of scratches, dings, nicks, scrapes, rust...rubber feet gone, level switches busted, that sort of thing, but its always worked. Its been one of those little projects in the back of my mind to recap it and clean it up. So I took part of an evening and did just that.

Here it is opened up before any work. Recapping was a little hairy for me because there are no symbols or screening on the PCB so I had to be extra mindful of paying attention to the orientation of the polar capacitors. I haven't done an audio test yet but nothing blew up when I plugged it in and powered it up so I'm hoping I got them all in right. :D

IMG_0981_2_1.JPG


IMG_0982_3_1.JPG


IMG_0983_4_1.JPG



Here it is with the new caps in it:

IMG_0984_5_1.JPG


I did all the usual stuff to it (cleaned everything well in and out, applied DeoxIT to pots and switches), but also repaired the level switches, found some replacement feet for it and repainted the case. I have a little touch-up to do on the dress panel yet, and it'll always be a little rough looking, but it was a worthwhile few hours spent on this unique analog effects box that will most certainly remain in my collection. ;)

I'll put up a couple pics of the finished project soon.
 
Last edited:
Cool. I once (late 90's) had a Peavey Reverb unit- don't recall how I got it, but I do remember it functioned as a low-power amplifier- I could plug my guitar into it, and it into a speaker, and it produced decent bedroom-level amplification.

Sold it for several times what I paid for it- which was probably several times LESS than what I could get for it, now.
 
Hello sweetbeats.

I have a dc-30 too,
and I'd like to do a good cleaning of the machin...

Seeing your post with your changes,
I have some questions to ask.

-Which component did you change?
I can see transistors...

-Have you got the shematics of the dc-30?
so where did you see the references of the components?
the component themselves?


Thank you very much for giving me some help.

I'd really like to give a youthful touch to the machine and its incredible sound!

Friendly,
nii
 
nii,

Hello fellow DC-30 owner! :)

The only components I replaced are the electrolytic capacitors which are the the light grey and/or light lavender "cans"

I made a list of what was needed by just looking at the capacitors on the PC board and then ordered them here in the US from Mouser. I used all Nichicon caps: PW series for power supply caps and KT series for audio path...there are a few bipolar caps and I can't remember what series caps I used for those but whatever I could get in a Nichicon brand that was hi temp (i.e. rated 105 degrees).

Below is a list of the value caps that were in my DC-30. You will want to cross reference with yours to see if they are the same value. "BP" means bi-polar or non-polar. All the rest of the caps listed are polar.

I have no idea if the new caps changed anything. I did it more for preventative maintenance than anything else. It may be quieter now but I don't know. I didn't want to change the sound.
 

Attachments

  • DC-30 caps.jpg
    DC-30 caps.jpg
    35.2 KB · Views: 923
Thank you sweetbetas for your answer!

I say transistor but it's capacitors...
I've got a really bad english...
So is what I saw


Thank you for the value caps list.
I'll look on my PC board, to check if the references are all the same.
(it's a french one...)
I went to take the screwdriver ;)

Even if the sound will be improved, as this will avoid leaking capacitors on the printed circuits.




Congratulations for your work!
And thank you for giving me all these details.
musically and friendly

nii
 
nii, your english is MUCH better than my french. :D

Yes, one of the main reasons I replaced my capacitors was to avoid them leaking. If it sounds better, then that is an extra good thing. ;)

Good luck. Post again if you have questions.
 
Hello sweetbeats,

Yes, I have questions.
I hope I will not bore you too...

For information capacitors in my unit are almost the same.
Only two refs are differents:
Four: 4,7uF / 35V
Two: 10uF / 50V BP
Are what you think the difference is important?



But i have questions,
What are capacitors used for power supply?
And what are capacitors used for audio?
I do not know how to differentiate
and do not think this is just the capacitors next to the power...


And have you an explanation, other than the ability of an hour, to the use of 105degree for BP?


Ok i stop it,
I'll burn your brain and mine too
;)



Thank you sweetbeats!!!
good evening
 
No bore. :D

  • The different caps: you would be fine to use the same values that are in your DC-30. It also wouldn't hurt to use the higher voltage versions that were in mine. You decide. Make your decision on what is available for you, but if it was a 4.7/25V cap you'll be fine replacing with the same values.

  • Look at this picture...the four caps circled in yellow are the ones I identified as being directly power supply related. The rest are assumed to be audio. Hope this helps:
    PSU%20caps.jpg

  • The higher temperature rated caps are just likely to last longer and handle long-term stress better. 105 degree BP caps ARE harder to find. It is okay to use 85 degree caps. If you have a choice it is usually a small cost to choose the 105 degree versions, but 85 degree versions should be fine too and last for many, many years. Think of how old your DC-30 is...everything works? No leaky caps? They are all 85 degree caps in there.

Hope that gives you a good view.
 
Ok thank you,
i've got all that i need!


Actually I was planning to caps having my own values. To avoid malfunctioning...

I bought this french unit DC-30 a few time ago. All the caps seems to be good (no leak) yet all they are 85 degrees.
But I prefer change them, if it is not too complicated, because his life will be extended. And I also hope that this will improve the sound, Even in a small way.

Thank you to show me the power supply's caps!

It remains for me to change them ;)
 
Back
Top