FB-01 noise/loudness issue

[tamla]

Cute unit, cost me next to nothing, but is it just my one or are they quiet with a large amount of "noise"? Having just purchased a bargain DX21 for only slightly more than the FB, I've probably got too many 4-op units...

[Clyde]

I only had my FB01 for a few months in the mid '80s and I don't remember it as having any more noise than the DX21 I had at the same time. If you are running into a mixer, then it could be a gain staging issue, the attenuation level (similar to mic/line level setting) of the mixer channel needs to match the output level of the FB01. Let us know a little more about your setup and we'll try to help.
Clyde

[tamla]

FB has both outputs connected to a line in of Tascam US428 via mono to stereo plug splitter cable.
FB output I believe to be at max - output value is at highest value (127), but playing around with my other synths into same line in for reference there is a massive difference in volume.
This could be an issue with my unit itself, as it looks slightly neglected. By comparison, everything else I own is in much better condition, and sound loud and clean running through this setup.

[Clyde]

Input on US428 should be set to line rather than mic, mono to stereo plug splitter could be causing an issue. No instrument should have volume levels set above 70-80 %, talking about audio levels only (no problem with op output levels at 100%), as it allows absolutely no headroom for transients. Different instruments can and do have higher/lower audio output levels, that is one of the reasons for being able to "pad" up or down the attenuation level on a traditional mixer, to be able to have all instuments at unity gain.
Clyde

[parametric]

Hi Tamla -

We used to use eight of these babies in one of our labs at the uni I worked at.
Low ouput was a problem - so we did a mod.
I've mailed my colleague who designed the mod to ask what it was.
I actually did the mod - but I can't remember the detail (it was about 18 years ago).

He's just moved to Thailand for a couple of years - but has offered to take a look if I send him the service manual - which I have just done.

I remember it being quite easy - so I'll await his reply and let you know . . . .

If you want the Service Manual, PM me your email address and I'll attach it . . .

The FB01 is a Yamaha peculiarity, in that I have it on good authority, that it was designed by Yamaha's HiFi Division rather than the Synth division. I believe that there are certain weirdnesses to the MIDI implementation which are probably the result of this "different parentage".

I'm thinking that it was probably meant to stand against Roland's MT32 which is also "car-radio" sized, but in my opinion wins this particular contest.

If you are wanting a small yamaha unit - then the MU5 is a lot better . . . .

Best Regards

parametric

[koa]

The FB-01 is in all points identical to the YM2151, just adressed differently

[koa]

plus it looks cool

[tamla]

Hi Tamla -

We used to use eight of these babies in one of our labs at the uni I worked at.
Low ouput was a problem - so we did a mod.
I've mailed my colleague who designed the mod to ask what it was.
I actually did the mod - but I can't remember the detail (it was about 18 years ago).

He's just moved to Thailand for a couple of years - but has offered to take a look if I send him the service manual - which I have just done.

I remember it being quite easy - so I'll await his reply and let you know . . . .

If you want the Service Manual, PM me your email address and I'll attach it . . .

The FB01 is a Yamaha peculiarity, in that I have it on good authority, that it was designed by Yamaha's HiFi Division rather than the Synth division. I believe that there are certain weirdnesses to the MIDI implementation which are probably the result of this "different parentage".

I'm thinking that it was probably meant to stand against Roland's MT32 which is also "car-radio" sized, but in my opinion wins this particular contest.

If you are wanting a small yamaha unit - then the MU5 is a lot better . . . .

Best Regards

parametric

Cool - I look forward to hearing the outcome of this as I've tried messing with everything and it still sounds quiet...thanks in advance.

[parametric]

Hi Tamla -

We used to use eight of these babies in one of our labs at the uni I worked at.
Low ouput was a problem - so we did a mod.
I've mailed my colleague who designed the mod to ask what it was.
I actually did the mod - but I can't remember the detail (it was about 18 years ago).

He's just moved to Thailand for a couple of years - but has offered to take a look if I send him the service manual - which I have just done.

I remember it being quite easy - so I'll await his reply and let you know . . . .

If you want the Service Manual, PM me your email address and I'll attach it . . .

The FB01 is a Yamaha peculiarity, in that I have it on good authority, that it was designed by Yamaha's HiFi Division rather than the Synth division. I believe that there are certain weirdnesses to the MIDI implementation which are probably the result of this "different parentage".

I'm thinking that it was probably meant to stand against Roland's MT32 which is also "car-radio" sized, but in my opinion wins this particular contest.

If you are wanting a small yamaha unit - then the MU5 is a lot better . . . .

Best Regards

parametric

Cool - I look forward to hearing the outcome of this as I've tried messing with everything and it still sounds quiet...thanks in advance.

Hey Tamla,

I just heard back from my colleague - he apologised for the long wait - but offers this mod as the solution he remembers . . . . and I quote:

The circuit is a little different from how I remembered it and I suspect I would have tested my solution to make sure it was ok. Unfortunately, I cant this time around but I vaguely remember the change being very simple - just a single resistor substition. If that was the case, then I suggest doubling the vaules of R6 and R13 shown on the final schematic of page 31 to 10K. The gain of the two output op-amps will increase from 3 to 5. I must have tested this with a scope to make sure it didn't clip.

I too remember it being a simple mod, which I did to all eight FB01s we had. The users seemed pleased with the outcome anyhow . . . .

As with all such mods, here in the forum, I have to add that the resposibility is yours if you try this on your FB01.

I really don't see any problems with it though - all I can say is that it worked for us . . . .

DO let us know if it performs better as a result - so others can benefit from this info


Best Regards

parametric

[tamla]

cheers for reply, haven't got round to it yet, have been busy with work and buying other studio goodies

[tamla]

still have not got round to doing this, and it's currently not midi'ed up as I swapped it out my rack for the Wavestation
Will report in once complete

[parametric]

Thanks for touching base tamla.
There's no rush.

parametric

[db7]

parametric, I wonder if you might know about this. I am very tempted to buy an FB-01 as a cheap multitimbral module and also because it has hardware very similar to the Mega Drive, as our band want to use some of its 4-op FM instruments but have found that the SY99 is (get this!) too clean compared to the extremely idiosyncratic and lo-fi output of the YM2612. [edit] Nah, it was the converter getting the op levels too low, not the SY99. Also, I mean that about the YM2612 in a good way, not as an insult! [/edit] But I have noticed, and had my suspicions confirmed by someone else online who recorded an album with the FB-01, that it seems to be noticeably lacking in treble (compared to the MD’s highly aliased signal, but also just in general). Whilst your suggested mod for volume is probably worth doing in any case, do you have any idea whether it might be possible to do something else in order to bring up the treble? If I could have an FB-01 with as punchy and broadband a signal as possible, that would be fantastic.

[koa]

You might want the TX81z instead. Its FM engine is the closest to what is implemented in the Sega Genesis.

[db7]

I’ve been thinking about a TX or even a V50, but I was wanting something that would be cheaper and also somewhat lo-fi. Given that the FB-01’s YM2164 is almost a YM2151, which is almost the same as the Mega Drive’s YM2612 (and which is the chip modelled by VOPM, which many people swear by for MD ‘emulation’), I always assumed that was closer.

Plus, the lo-fi aspect of the FB-01 would appeal to me, were it not for the considerably attenuated treble that it seems to suffer from. As I said, I know that a lot of the MD’s apparent treble and grit are just due to the various distortions introduced by the, ahem, quirky nature of the YM2612 (aliasing, TDM-based mixing and the associated spikes, etc.), but other elements of lo-fi come from the DAC, the way the chip generates waves, and so on, and I thought the FB-01 would be a quick and easy way to get sort-of-a-Mega-Drive with MIDI.

The SY99 can import instruments from the MD via vgm2opm, DXconvert, and a DX-to-SY converter such as the recently released d2s.py on the YamahaDX Yahoo group, but as I said, they almost sound too clean. Not something I’d normally complain about, but some instruments actually depended upon the YM2612’s weirdness, it seems!

You’re tempting me to get back in touch with that guy about the V50, though… even though it’s much the same as cutting in half my SY77, which I’m already thinking I should probably sell. :S

Edit: Something else it would be handy to know: does anyone know whether the FB-01 or V50, unlike the TX81z, can execute program changes from MIDI without a noticeable delay in playback on that channel? This would be necessary for full-track emulation of songs from the MD, but I presume it could also be important in some other contexts.