I've gone through most of my stash looking for cards I either know need -5V or I can visually verify have the B5 (-5V) ISA finger contact and are routing it to components on the ISA card.

I've also read certain Pro Audio Spectrum cards require -5V, but I don't have any to verify that.

I'd think most old cards with audio amplifiers and differential drivers would require the negative voltage rail.

QBiN wrote:

I've also read certain Pro Audio Spectrum cards require -5V, but I don't have any to verify that.

Most PAS16 cards do. I have the original PAS and the very late PAS16 (Pro Audio 16 XL SCSI), they don't.

QBiN wrote:

[*]Roland LAPC-I - LA Synthesizer + MPU-401 Card - Symptom: ??

Only MPU part works without -5V, the LA synthesizer part is silent.

Harekiet wrote:

I'd think most old cards with audio amplifiers and differential drivers would require the negative voltage rail.

Thing is a bunch of more modern ones actually derive it from the -12v rail (as does the OEM GUS I'm cloning).

shock__ wrote:

Harekiet wrote:

I'd think most old cards with audio amplifiers and differential drivers would require the negative voltage rail.

Thing is a bunch of more modern ones actually derive it from the -12v rail (as does the OEM GUS I'm cloning).

I think most "newer" ISA cards do this. It's much better, since a linear regulator like 7905 has very little noise compared to a switching converter. Cards with a chipset that doesn't need -5V (like YMF71x) still make their own +5V from the 12V rail for the analog parts.

bristlehog wrote:

QBiN wrote:

I've also read certain Pro Audio Spectrum cards require -5V, but I don't have any to verify that.

Most PAS16 cards do. I have the original PAS and the very late PAS16 (Pro Audio 16 XL SCSI), they don't.

Do you know which rev/models #'s of PAS16 require the -5V rail?

650-0044 56B (FCC ID: IXW-PAS16NS) seems to be one such candidate.

http://www.yjfy.com/images/oldhard/sound/Pro_ … Spectrum_16.jpg

650-0066-02 (FCC ID: IXW-JAZZ16) connects the -5V rail to the LF353N op-amp ... Symptom should be no audio/low volume on one of the outputs (seeing how this card supports its' own standard along with OPL3).

Will try to verify once I get my 486 shipped to my place.

Strangely my PAS Plus has the finger, but it goes nowhere... But it's a strange board, possibly an OEM version; has no joyport and instead has a big connector for a breakout box. It uses the -12V rail though and the amp is grounded only through the slot bracket.

QBiN wrote:

Do you know which rev/models #'s of PAS16 require the -5V rail?

Problem is there's a giant bunch of PAS16 cards: old, new, with SCSI, LMSI, Sony or even no CD interface. A dozen of them or even more. I don't particularly know which ones are affected. But Cloudschatze once said that only the latest (650-0097) doesn't require -5V rail to operate properly. If he's right, then all others are guilty.

There are also PAS Plus (650-0014) which doesn't need the designated rail, and a shady card that I saw on ebay twice but missed the opportunity to buy: 650-0018. It resembles PAS Plus but has two jacks instead of three. It's unclear whether it is a late version of PAS Plus or an early version of PAS 16 (whose numbers usually start from 650-0022).

HighTreason wrote:

Strangely my PAS Plus has the finger, but it goes nowhere... But it's a strange board, possibly an OEM version; has no joyport and instead has a big connector for a breakout box. It uses the -12V rail though and the amp is grounded only through the slot bracket.

What is the 650-xxxx number of your PAS Plus?

It says 650-0018 01-B. The 01-B is written in marker pen.

I will check my other cards for -5V.

I own 3 Pro Audio Spectrum cards.

Pro Audio Spectrum Plus - 650-0014
Pro Audio Studio 16 - 650-0052
Pro Audio Spectrum XL - 650-0097

Both the Plus and XL do not require -5V but the Studio 16 does. The great majority of branded PAS 16 cards do require -5V.

HighTreason wrote:

It says 650-0018 01-B. The 01-B is written in marker pen.

I will check my other cards for -5V.

Interesting. Have the pic? How do you know it's a PAS Plus, not PAS 16?

I have an ISA Soundblaster AWE64 (CT4520) and it must not require -5V since the PSU I'm using has no -5v rail.

bristlehog wrote:

But Cloudschatze once said that only the latest (650-0097) doesn't require -5V rail to operate properly. If he's right, then all others are guilty.

Here's what I'd written about the affected PAS16 cards:
MediaVision - PAS16? - Help ID the card - Help with drivers

Note the speed-related playback symptoms through the 8/16-bit CODEC when -5V isn't present.

HighTreason wrote:

It says 650-0018 01-B. The 01-B is written in marker pen.

This is Media Vision's earliest CDPC interface card. It is compatible with the PAS+, as referenced in the PAS SDK, and was designed to connect to an external CD-ROM unit having built-in speakers, audio and MIDI I/O, and a joystick port.

Cloudschatze wrote:

HighTreason wrote:

It says 650-0018 01-B. The 01-B is written in marker pen.

This is Media Vision's earliest CDPC interface card. It is compatible with the PAS+, as referenced in the PAS SDK, and was designed to connect to an external CD-ROM unit having built-in speakers, audio and MIDI I/O, and a joystick port.

So does the CDPC card need the -5V as well? That wasn't clear to me in the posts.

Sound Blaster Pro CT1330A: does not need -5V. Finger B5 does not exist on the PCB.

QBiN wrote:

So does the CDPC card need the -5V as well? That wasn't clear to me in the posts.

I don't have one with which to verify, but HighTreason mentioned that the bus finger doesn't go anywhere on the card, so it doesn't sound like it.