Dual Photocouplers (Xvive Reissues)

[benny_profane]

FYI for phaser, filter, etc. kids (and anyone sitting on a Sawse board), SBE has dual photocoupler reissues from Xvive in stock.

(VTL5C4/2 and VTL5C3/2)

[madbean]

Oh cool! A 4/2!

[somnif]

Ooo, groovy, time to dust off some old filtery goodness, maybe a phaser or two...

[benny_profane]

Oh cool! A 4/2!

Any chance sawse could come out of retirement?

[Yahoo67]

Yay i still got my sawse from the bundle ^^ next time i order from small bear i will grab one

[madbean]

Oh cool! A 4/2!

Any chance sawse could come out of retirement?

Yes I definitely would. I might want to get one of them first so I can test it against my OG build.

[benny_profane]

Oh cool! A 4/2!

Any chance sawse could come out of retirement?

Yes I definitely would. I might want to get one of them first so I can test it against my OG build.

Very cool. Yeah I'm interested to see how these work out.

[somnif]

Question for the crowd, what is the actual "off" resistance of the 4/2? The data sheet has what I seriously hope is a typo, stating that the "on" resistance is 1.5k, and the off is... 400 ohm?

The graph shows the off resistance going off the chart, so either I'm fundamentally misunderstanding something, or there is a typo.

[madbean]

Don't recall off-hand but that is obviously a typo. The thing about the 4/2 is not only the on/off resistance but the actual response time (decay). I recall that at least with the Sawse project the 4/2 is the only vactrol that works. The 3/2 does not respond correctly.

[somnif]

Don't recall off-hand but that is obviously a typo. The thing about the 4/2 is not only the on/off resistance but the actual response time (decay). I recall that at least with the Sawse project the 4/2 is the only vactrol that works. The 3/2 does not respond correctly.

Yeah its always the response time that is tricky in designs, and usually a pain to figure out from datasheet alone.

Personally I'm curious how well they would compare to the unobtanium hamamatsu dual vactrols sitting in things like the ibanez flying pan or maxon rotary phaser. Given how painfully pricey both parts were its not something I could easily side-by-side test, and my digging hasn't shown much (beyond BYOC's "custom made" examples they include in the FP-777 kit).

[somnif]

Well the plot thickens, its pretty much agreed that the 400 ohm "off" resistance is a misprint. But, what the actual resistance is? ....apparently misprints are common with this thing.

Some old datasheets say 400 Meg Ohm, some say 400kOhm. Apparently similar discrepancies are present for the VTL5C4 single version as well, some say 400M some say 400k.

Why oh why can't people proof read these things...

[alanp]

Obvious answer would be for someone to buy one and test it themselves.

[benny_profane]

Why oh why can't people proof read these things...

Technical writing is the Wild West.

[Govmnt_Lacky]

You can probably bank on it being 400Kohms. Simply because 400M is a VERY high resistance and close to simply being open. I cannot think of a reasonable measuring tool that can measure that high of a resistance.

[midwayfair]

You can probably bank on it being 400Kohms. Simply because 400M is a VERY high resistance and close to simply being open. I cannot think of a reasonable measuring tool that can measure that high of a resistance.

People measure 1G resistors. Someone measured a diode's resistance for me a while back that was in that range.

400M is not out of the question. The VTL5C1 is 50M dark.

If I had one that wasn't in a circuit right now I'd just measure it. Surely someone around here has one.