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Seen that, probably will use it in my build. I don't care for metal covers for LDR's

Bob Sweet used "open" type, as well as the bloke behind Mega Vibe

sinner wrote:Seen that, probably will use it in my build. I don't care for metal covers for LDR's

Bob Sweet used "open" type, as well as the bloke behind Mega Vibe

Fulltone uses the metal LDR's.

A couple of things...

Awhile back I bought a broken Uni-Vibe for $600 with the intent of repairing and flipping it. There ended up being more wrong with it than the seller mentioned so I sent it off to NOS Tone who specializes in vibe repair. After looking it over, he seemed to feel it definitely was an earlier unit based on the following...

1) It had the dual think rubber strips on the speed control pedal as opposed the single rubber strip.
2) There was no trim pot for the lamp (although someone had added one).

Other than the mod and one incorrect resistor, they seemed to feel the unit was original. The mod was reversed, the transistor replaced with a NOS correct one and the unit shipped back to me. It was hands down the best vibe I have ever played and I seriously thought about holding onto it but I wasn't in the position to and I had an offer that doubled my investment. I have however stayed in touch with the buyer and he was kind enough to let me borrow it to make some notes for this thread. The unit matches schematic variant #1 with Q1 being a 2SC539 and the rest being C828's.

Now I happen to have a Fulltone mini Deja Vibe here as well and there are some differences. The speed pot is a B100K which completely blows for adjustability, all the travel is bunched up at one end and I cannot understand why a C100K was not used. The 100K mix resistor is was swapped for an 82K, bumping it back up to 100K adds too much vibrato and dropping it to 47K gets it closer to sounding like the original unit but something's still not right. The original is much warmer sounding than the Fulltone and "vibes" differently. I've tried adjust the lamp trimmer on the Fulltone and have gotten it closer to the original but something just isn't cutting it. The Fulltone is also done in a very tight layout, all the resistors are standing on end so ID'ing them all is a pain on the ass (not to mention following the traces) but so far I've also noticed an 18K and 680r that don't match the info we have. My intent was to RE the Deja Vibe and mod it back to original specs but it now seems to be more trouble that it's worth so I suspect I will just build my own.

What sort of amuses me is that you often read about matched LDR's being the source of mojo but I'm guessing like most vintage pedals, matching was not a concern and whatever was grabbed from the parts bin is what got used. Another note...the dimensions of the light shield in both the original and the Fulltone is 1.75" sq. x .75" high.

Bottom line, I'm sorry I sold the original but at least I have access to it.

Awhile back I bought a broken Uni-Vibe for $600 with the intent of repairing and flipping it. There ended up being more wrong with it than the seller mentioned so I sent it off to NOS Tone who specializes in vibe repair. After looking it over, he seemed to feel it definitely was an earlier unit based on the following...

1) It had the dual think rubber strips on the speed control pedal as opposed the single rubber strip.
2) There was no trim pot for the lamp (although someone had added one).

I's still on hunting for info, and I think I'm getting to have it systematized. As for today it looks like the early models was done by Shin-Ei and externally had light gray enclosure, white in-printed logo, gray power cord, and internally often seen jumpered trimmer, 2x1k8 instead of 4k7 (R45, R46 on my schematic) in later units, and 100k instead of 47k (R37). I'm still not sure about C7/C9/C13/C16 caps as they're often not clear to read.

If you have it right now could you check above values, or/and take sharp picts?

Other than the mod and one incorrect resistor, they seemed to feel the unit was original. The mod was reversed, the transistor replaced with a NOS correct one and the unit shipped back to me. It was hands down the best vibe I have ever played and I seriously thought about holding onto it but I wasn't in the position to and I had an offer that doubled my investment. I have however stayed in touch with the buyer and he was kind enough to let me borrow it to make some notes for this thread. The unit matches schematic variant #1 with Q1 being a 2SC539 and the rest being C828's.

So you say it was matched to factory schemo? There is one resistor error on factory schematic for 915 unit. R47 (47k on 915 factory schematic) was in fact 4k7. Proved in number of gutshots, as well as by RG. Keen, you're sure your tech didn't change the right resistor?

Now I happen to have a Fulltone mini Deja Vibe here as well and there are some differences. The speed pot is a B100K which completely blows for adjustability, all the travel is bunched up at one end and I cannot understand why a C100K was not used. The 100K mix resistor is was swapped for an 82K, bumping it back up to 100K adds too much vibrato and dropping it to 47K gets it closer to sounding like the original unit but something's still not right. The original is much warmer sounding than the Fulltone and "vibes" differently.

Perhaps fulltone changed the input resistors to compensate volume loose, it brights the signal AFAIK. Stupid, popular mod that everyone seems to use :/ "calling it after the closes replica you can get"

The Fulltone is also done in a very tight layout, all the resistors are standing on end so ID'ing them all is a pain on the ass (not to mention following the traces) but so far I've also noticed an 18K and 680r that don't match the info we have. My intent was to RE the Deja Vibe and mod it back to original specs but it now seems to be more trouble that it's worth so I suspect I will just build my own.

Could you get the film/ceramic cap values, this might be interesting. AFAIK (I think B.Man told me) KR Megavibe bloke mask the values for this capacitors making it big secret. Other units from past era like Shin-ei/915/905/JAX and others have a different C7/C9/C13/C16 arrangement. It's all in signal/audio patch so it should affect the tone.

RG.Keen said someware that he seen at least three circuit variants, two are known to me, they're on my website, I wonder what's the third one can be. Perhaps he was thinking about Vibra-Chorus (Shin-Ei brand, not the Companion, and OEMs), as it looks like the Uni-Vibe? I have no notes at all (yet) about Vibra-Chorus unit. Other known variants like JAX (Companion) Boomer, Nomad, Shin-Ei RT-18/PT-18 looks different, and they have extended options, not to mention Psychodelic Machine.

What sort of amuses me is that you often read about matched LDR's being the source of mojo but I'm guessing like most vintage pedals, matching was not a concern and whatever was grabbed from the parts bin is what got used.

I think it's marketing BS. It's like "hey, we make the best motherfucking univibe clone, it's more than accurate, it's bloody exact, and we build our own photocells made of 1 milion year old dead dinosaur urine, and we match them the secret way only good God may know" - fuckit

Another note...the dimensions of the light shield in both the original and the Fulltone is 1.75" sq. x .75" high.

Awesome, thanks for that, this was the info I didn't know who to ask. Do you think it's possible to open the can and see does it reflective? It looks like some guys swears they are, and others they didn't...

Bottom line, I'm sorry I sold the original but at least I have access to it

Do you think you could take shitload of picts, as well as do some extended measuring? Like the enclosure dimensions, transformer secondary voltage (it looks like it makes big debate what the real voltage was), and perhaps all transistor voltages too?

And most important thing - Big thanks bro, you're awesome

The Rotagilla wrote:1.75" sq. x .75" high.

You sure it's not 1.25" square?

I have just added more blah, blah about that Shin-Ei Vibra-Chorus, and the enclosure recommendations

More info, and files will be added shortly

1) Unfortunately I had to return it yesterday morning before I posted. While the guy was nice enough to loan it to me, he was understandably anxious to get it back. I'll hit him up again in a few weeks to see if I can get it again.

2) You're right, the light shield is 1.25" x .75" and is brightly polished on the inside (as is the Fulltone).

3) It appears we now have a third variant of the schematic. It matches the corrected 915 one with R45 and R46 both being 1K8. R47 is indeed a 4K7.

4) The caps in the Fulltone were the first thing I checked. All electrolytics were 1.5uF (mentioned earlier) and the film/ceramics match the 915 schematic.

I will take my notes, match them to Sinner's schematic and send a complete schematic to him this weekend.

Nice thanks a lot. I was going to ask about the mounting holes locations, but maybe when I'll have it again

Would you want to have the schematic .diy file?

Here's the older Deja-Vibe version BTW http://www.tcgakki.com/items03/tc036181.html#photo he used to use 1uF back then

While you're on your Deja-Vibe, could you check what the vintage/modern switch does?

sinner wrote:While you're on your Deja-Vibe, could you check what the vintage/modern switch does?

I believe it switches between two resistor values, my notes are at work so I'll fill you in this weekend. I'll also provide you with the changes and match them to you schematic numbers.

Good news, I got the original back so PM what you need and I'll get it to you.

Now I'm horny

PMd

Btw, does anybody have an access to shin-ei brand vibra-chorus? The one in traditional univibe form, with cancel switch, and speed pot on board is what i'm after

Funky cheers

My Univibe build doesn't use matched LDRs and I still get good results, the lamp driver transistor, an MPSA 14, gets a bit too hot for my liking so I'm going to try replacing it with something a bit more beefier....

I made the light shield for the LDRs and Lamp from some tinplate I scrounged from an old Mac G3 computer, because tinplate is solder-able, I just needed to solder the parts of the light shield together, seems to work fine.....

DrNomis wrote:My Univibe build doesn't use matched LDRs and I still get good results, the lamp driver transistor, an MPSA 14, gets a bit too hot for my liking so I'm going to try replacing it with something a bit more beefier....

I made the light shield for the LDRs and Lamp from some tinplate I scrounged from an old Mac G3 computer, because tinplate is solder-able, I just needed to solder the parts of the light shield together, seems to work fine.....

Univibe makers in the past propably used umatched LDRs, as well.
Anyway, maybe unmached LDRs with different parameters in particular phase steps will sound better than matched quartet.

Even if they did - let's look on it from different spot

Now we have 2012 and the part tolerance is way greater and tighter than in 60's right? I didn't look on Silonex datasheets yet, but I'm sure they have at least 5% tight tolerance. AFAIK usually at the factory plants if the part doesn't fall into the tolerance bucket, then it's issued under different part number. Like the transistors. BC108, and the 107 are the same parts spec-wise, the difference is in gain bulk. I suspect we may have similar situation here, but as I said. I did not look on the data yet

In short - fukit, I wont match them, to much wanking IMO. It's Grand-Wanker to build anyway

I think Fumio Mieda - the Uni-Vibe inventor is still alive... who knows how to contact him? Perhaps I could email him with few questions, like the LDR mystery

beedotman wrote:

DrNomis wrote:My Univibe build doesn't use matched LDRs and I still get good results, the lamp driver transistor, an MPSA 14, gets a bit too hot for my liking so I'm going to try replacing it with something a bit more beefier....

I made the light shield for the LDRs and Lamp from some tinplate I scrounged from an old Mac G3 computer, because tinplate is solder-able, I just needed to solder the parts of the light shield together, seems to work fine.....

Univibe makers in the past propably used umatched LDRs, as well.
Anyway, maybe unmached LDRs with different parameters in particular phase steps will sound better than matched quartet.

I think whether to use matched LDRs or not is really up to the individual builder of a Univibe, I'm thinking that in those days when the Univibe was first manufactured, LDRs probably cost a bit more than they do today, especially for accurately matched ones so the manufacturer probably did use whatever was avalible, ultimately what works for you is what you should use, unmatched LDRs will probably give varying responses per phasing stage, but remember that each phasing stage is bootstrapped and therefore has a really high input impedance and low output impedance so I reckon that the differences per LDR would probably be swamped-out anyway....

My theory anyway....

Light shield blah blah and PDF plans are on

Transfer file was also revised, it needs no to be inverted as I said earlier. Other than that it's the same crap

Also I came across the footprint dimension of the univibe. It's 10" x 7" so it's close to the bigger enclosure recommendation (Hammond 1550J)

The link http://www.turretboard.org/?p=2213

sinner wrote:I think Fumio Mieda - the Uni-Vibe inventor is still alive... who knows how to contact him? Perhaps I could email him with few questions, like the LDR mystery

Mieda is head of design for Korg nowadays. Contact korg.

Dirk_Hendrik wrote:

sinner wrote:I think Fumio Mieda - the Uni-Vibe inventor is still alive... who knows how to contact him? Perhaps I could email him with few questions, like the LDR mystery

Mieda is head of design for Korg nowadays. Contact korg.

Thanks

I suspect he will tell me to fly the kitty when he'll find out I have the UV replica files online...

I'll try anyway