Next H3000 issue: subtle glitches on some patches. A few leads...

[soapfoot]

Once I got the trash-picked H3000 up and running again, I thought it was fixed. Then the other day I dialed up the "Dual H910s" patched and noticed some strange behaviors. Ran a 1k tone in just to see what was going on, and it made the glitches more apparent.

Here's what it's doing:

Looking through the service manual, something in particular caught my eye:




And here is the schematic of that area:



I did notice that R150 is specified 8k8 on the schematic, but the actual value in the unit is 8k2. This appears factory, so I doubt it's the problem, but worth noting.

I'm not sure whether I'm even looking in the right area. I have a somewhat old and primitive oscilloscope (Protek P-3502C, 20MHz) and I crudely probed around various ICs trying to find data bus lines and anything that looked amiss. Honestly, I'm not sure I was even qualified to know what I was looking at.

But I will say the machine appears to behave entirely normally except for these weird glitches on output on only some patches.

I'd appreciate any leads. I'd love to fix it myself.

I suppose I could just start replacing things, beginning with that 8k2 resistor and maybe U193, but something tells me that more intelligent, targeted troubleshooting might be a better idea on a machine with relatively-fragile PCB traces and a lot of non-socketed ICs.

 

[living sounds]

What happens if you set the device to the basic setting decribed in the service manual: program 102, pitch shift 1.0 on both channels, delay parameters both to zero?

I finally managed to get a hold of the H3000 self test, if you have a prommer this might be helpful.

 

[soapfoot]

What happens if you set the device to the basic setting decribed in the service manual: program 102, pitch shift 1.0 on both channels, delay parameters both to zero?

I finally managed to get a hold of the H3000 self test, if you have a prommer this might be helpful.

Super helpful! I don't have a prommer, but it seems like a cheap one is about 14 bucks on Amazon?

I'll perform the test you mentioned now

 

[soapfoot]

What happens if you set the device to the basic setting decribed in the service manual: program 102, pitch shift 1.0 on both channels, delay parameters both to zero?

Completely clean and glitch-free. Both with the patch defaults loaded, and with the pitch shift and delay parameters set as above.

Is this a clue?

 

[living sounds]

It might be normal behaviour. I think mine does this, too. I will check if it is truly ok once I got the eproms, too.

A cheap chinese prommer might not cut it (but I don't know, I've asked someone with a pro level prommer to burn it for me). Also read the attached pdf, depending on your jumper settings either 512 kb or 1MB eproms are required.

 

[soapfoot]

It might be normal behaviour. I think mine does this, too.

Okay, I'd really appreciate this! Thanks so much

 

[radardoug]

Apparently there are people who love those 910 glitches, which the original unit did.

 

[TheJames]

What happens if you set the device to the basic setting decribed in the service manual: program 102, pitch shift 1.0 on both channels, delay parameters both to zero?

I finally managed to get a hold of the H3000 self test, if you have a prommer this might be helpful.

This is amazing! Thanks for the ROM image!!!

 

[plimousse]

Hi,
Thanks for the ROM image
Cheers,

 

[mrclunk]

I finally managed to get a hold of the H3000 self test, if you have a prommer this might be helpful.

Thanks for this!

 

[soapfoot]

If someone had a prommer, I bet they could sell a few self test ROMs on eBay.

I’d be in for one at 20 bucks, probably

 

[living sounds]

If someone had a prommer, I bet they could sell a few self test ROMs on eBay.

I’d be in for one at 20 bucks, probably

I'd advise caution with trying to sell a third party's intellectual property on the internet for profit...

 

[soapfoot]

Hm, interesting point!

Several vendors seem to sell the H3500 EPROMs with no apparent issue.

Could it be considered abandonware at this point? Eventide no longer supports the H3000.

 

[plimousse]

Yes, but some technician work and support the H3000.

 

[soapfoot]

Yes, but some technician work and support the H3000.

Do they have any IP ownership of the information on the EPROMs though?