VOGONS


First post, by zuldan

User metadata
Rank Member
Rank
Member

Just received a SC-55MKII. I thought it would be a good idea to test the voltage coming from the power adapter before powering on the unit. The reading from the multimeter is 13v? I thought it was supposed to be 9v. Maybe it's supposed to be 13v and then when plugged in it goes down to 9v from the circuity load.

Is anyone able to measure the voltage from their power adapter and let me know what voltage you are getting?

Roland2.jpg
Filename
Roland2.jpg
File size
212.48 KiB
Views
314 views
File license
Public domain
Roland1.jpg
Filename
Roland1.jpg
File size
223.22 KiB
Views
314 views
File license
Public domain

Reply 1 of 6, by keropi

User metadata
Rank l33t++
Rank
l33t++

this is an unregulated PSU, it needs load to output the rated voltage
once powering the SC-55 voltage will be fine

🎵 🎧 PCMIDI MPU , OrpheusII , Action Rewind , Megacard and 🎶GoldLib soundcard website

Reply 3 of 6, by zuldan

User metadata
Rank Member
Rank
Member
keropi wrote on 2024-01-30, 08:29:

this is an unregulated PSU, it needs load to output the rated voltage
once powering the SC-55 voltage will be fine

Thank you so much for that information. Is it recommended to replace the original PSU (31 years old) with a Roland PSB-240A? Or are the original PSUs pretty robust? I don’t want to damage my unit with bad power.

Reply 4 of 6, by zuldan

User metadata
Rank Member
Rank
Member
pc-sound-legacy wrote on 2024-01-30, 08:51:

If you consider using another psu anyway, please keep in mind that the polarity is plus outside and minus inside - vice versa to most other PSUs.

Thanks for the heads up!

Reply 5 of 6, by Shponglefan

User metadata
Rank l33t
Rank
l33t

I just use generic RCA multivolt adapters with my various Roland sound modules. As long as you have enough milliamps, 9v and tip negative polarity, any decent power supply will be fine.

Pentium 4 Multi-OS Build
486 DX4-100 with 6 sound cards
486 DX-33 with 5 sound cards

Reply 6 of 6, by midicollector

User metadata
Rank Member
Rank
Member

Here is Roland’s official guide to which modern psus to use in old hardware: https://www.rolandus.com/assets/press_media_r … dapterGuide.pdf

The sc55 2 should use a psb-1u, which today is replaced by the psb-120, which is what I use for my sc55.