ARP Soloist repair (pre Pro-Soloist, moved from Burn thread)

[JoJoB3]

Moving the (out of topic ARP Soloist) posts from the GSi Burn thread. Very close to till some questions remain.

 

Early Post:

 

Problem -

Thanks. My hunt for Arp specialists is how I found this forum (but...I think this one's gonna be tough. 1971 Arp Soloist has a bad original 4027 sealed circuit that needs work. Problem: epoxy sealed. Ugh. But my lord am I attached to this thing, almost as much as hammond).

 

Early ARP Soloist (non "Pro-Soloist)exactly like this one:

http://www.performing-musician.com/pm/mar08/images/RetroSpecProSoloist_01.jpg

 

 

Update: EPOXY is thick black, heavy grade rather than the white silicone. Impossible to remove without further component damage, even with all heat techniques applied.

Onward we move!

 

Only realistic fix is replace with a 3rd party remake of the 4027, thankfully they exist - kudos to humans!!

 

I bought the 4027 remake via ebay (ARP 2600. 4027 oscillator module. NEW - http://www.ebay.com/itm/310825867275) and will have it installed by my tech. The other suggz (thanks btw) did not respond to emails/calls, this was the only option). Hope it arrives sooner than later, I want to take it out on upcoming tours.

 

Can I ask those in the know the major differences between these remake 4027s and the original 4027s in regard to sound?

Will the tone (wonderful fat tone) be changed drastically with this remake 4027 (aside from issue fix) versus the original 4027? Or will any differences be negligible?

 

The other item of repair I really want to try and resolve is the "conductive foam" (which is what allows for this ARP special expressiveness, very important).

Can anyone guide me to resources/persons/companies who might be able to sell this (or equiv) conductive foam?

 

Are there other optional routes to repair as well?

 

*The concept of the conductive foam and expression: Early aftertouch, press down on a key and the entire keybed moves downward to have the contacts at each end meet and activate any/all of the chosen expression effects activated on the Soloist. It's really something else, totally in love with this thing.

My conductive foam is simply gone/rotted away. Bits remain, but the ARP is still currently activating/working this expression...but not as well as it could I imagine and I'd love to fix that.

 

Google searches brought nothing, but perhaps I'm not searching the specific name of such conductive foam.

 

This ARP will be used as long as I can keep it functional, but a good example of it's use (when it was working) is on the following track on the Vol 2 CD (hammond B3 + ARP Soloist on top).

http://mctuff.bandcamp.com/track/better-weather

 

Thanks for any and all info!

[jverghese]

Hi,

 

Good to hear you found a replacement module, and thanks for starting this new thread, btw!

 

As for the differences between the 4027 and 4027-1, the latter is a simplified design using less circuitry and having fewer pins connecting to the motherboard. The 4027 requires high frequency tracking to be trimmed, whereas the 4027-1 is internally compensated. If you replace a 4027 with a 4027-1, the HF trimmer (located on the motherboard) will have no effect.

 

Sound-wise, I don't think the 4027-1 will be different from the 4027. The 4027-1 may have a little more frequency jitter, but that would only be audible in a multi-VCO synth like the 2600. Jitter performance can be tested by tuning the VCO against a stable reference signal (or antoher VCO). As you approach perfect unison, the beating will slow down. A low-jitter VCO will allow clean, slow beating at an interval of several seconds. But, as mentioned, jitter has less of an impact in single-VCO synths.

 

The pressure sensor thing is tricky. Maybe you could ask your tech if he has a source for conductive foam? IC chip manufacturers often use foam to protect devices from static electricity during shipping. Don't know if it's usable for pressure sensing, though.

 

-joachim

 

[Losendoskeys]

Hi,

 

Good to hear you found a replacement module, and thanks for starting this new thread, btw!

 

As for the differences between the 4027 and 4027-1, the latter is a simplified design using less circuitry and having fewer pins connecting to the motherboard. The 4027 requires high frequency tracking to be trimmed, whereas the 4027-1 is internally compensated. If you replace a 4027 with a 4027-1, the HF trimmer (located on the motherboard) will have no effect.

 

Sound-wise, I don't think the 4027-1 will be different from the 4027. The 4027-1 may have a little more frequency jitter, but that would only be audible in a multi-VCO synth like the 2600. Jitter performance can be tested by tuning the VCO against a stable reference signal (or antoher VCO). As you approach perfect unison, the beating will slow down. A low-jitter VCO will allow clean, slow beating at an interval of several seconds. But, as mentioned, jitter has less of an impact in single-VCO synths.

 

The pressure sensor thing is tricky. Maybe you could ask your tech if he has a source for conductive foam? IC chip manufacturers often use foam to protect devices from static electricity during shipping. Don't know if it's usable for pressure sensing, though.

 

-joachim

 

Joachim!

 

I didn't know you frequented these parts!

You'll find I sing the praises of your Prosoloist Rack + all over this forum

 

The OP doesn't say where in the world he is located......I have a UK synth engineer who fixed two ProSoloists for me.

 

R

Alan

[yorgatron]

have you been to http://www.vintagesynth.com/forum/ yet?

 

 

[JoJoB3]

I'm in the U.S. (Seattle).

 

No I didn't join that forum (not seeing a lot of real "vintage" synths like these over there really btw. Even a simple search for ARP delivers nothing).

 

Good news on the replacement part, hoping it works out.

My tech is helping the search for the conductive foam, but I'd like to know if it goes by other names.

[yorgatron]

 

No I didn't join that forum (not seeing a lot of real "vintage" synths like these over there really btw. Even a simple search for ARP delivers nothing).

 

 

because "arp" is only three letters, and the search function doesn't work for words that short.

 

however, if you type in "arp pro solist" like I did, you get 17 pages of results.

 

YOU'RE WELCOME!

 

 

 

[Tobias Åslund]

I must ask, since we have mr Verghese in this thread - is the ProSoloist Rack still being made?

[JoJoB3]

Oh for christ's sake, you're right (arp search). But not seeing a lot of tech talk on it. 99% of it are posts on who played the arp, etc. I think the new part should do the trick, but maybe they'll know where to get the conductive foam. thanks

 

 

because "arp" is only three letters, and the search function doesn't work for words that short.

 

however, if you type in "arp pro solist" like I did, you get 17 pages of results.

 

YOU'RE WELCOME!

 

 

[Losendoskeys]

I must ask, since we have mr Verghese in this thread - is the ProSoloist Rack still being made?

It's now the Rack+ :

 

http://i342.photobucket.com/albums/o430/alanjpearson/psp3sm-1_zps2c4e7fe4.jpg

[Tobias Åslund]

Thanks, I know about the new version, but there doesn't seem to be much info about it anywhere, so I'm not sure it really is still available... Do you know for sure, it's still possible to order one?

[Losendoskeys]

Thanks, I know about the new version, but there doesn't seem to be much info about it anywhere, so I'm not sure it really is still available... Do you know for sure, it's still possible to order one?

I was in contact with Joachim a few weeks ago.

 

He is concentrating on his new project - to build a Hammond L122 "clone".

I was pestering him for the new firmware for the Rack + which gives you Quadra and 2600 sounds.

But I'm sure he would ship you one if you asked nicely

[WesG]

An L122 clone? Seriously? I'm drying to know why. I mean, I play L100s and they sound fine, but I would rather play a console organ..

[Losendoskeys]

An L122 clone? Seriously? I'm drying to know why. I mean, I play L100s and they sound fine, but I would rather play a console organ..

 

Luckily for me Joachim is a big Genesis fan, so in building his Prosoloist Rack he solved the big problem of how to get ARP sounds - not possible with sampling due to the ProS switchable effects.

Having now built in the Quadra and 2600 sounds he has also put together the next difficult sounds that Banks used.

 

I'm not sure why he is embarking on the Hammond L100 (and T-series) project but believe me, if ANYONE was going to nail the sounds from those organs he will!

And it's almost certainly because he wants to, not because there is a commercial benefit in it, from what I can see.

 

R

Alan

[Tobias Åslund]

An L122 clone? Seriously? I'm drying to know why. I mean, I play L100s and they sound fine, but I would rather play a console organ..

Well, if you're playing only jazz, that statement might make sense, but for us playing in loud rock bands - the L100 tone is really usefull. Just my 0.02!

 

And - thanks Losendoskeys for the info!

[The Real MC]

My Porta-B is a roadable L-100 that I have owned since 1981, and it is a SCREAMING organ. I've had B-3 snobs who loved it after they played it.

[jverghese]

Hi,

 

Thanks for all the kind words, Alan, much appreciated.

 

My visits here are rather sporadic (as you should be able to tell by now). I would love to contribute more often, but simply don't have the time. I felt obliged to respond to JoJoB3's request for help with his ARP Soloist, it's such a great thing that people still want to keep those things alive -- and make great music with them too.

 

As for my ProSoloist+ rack project, it's still a work in progress. As you may know, it will include models of not only the ProSoloist, but the lead section of the ARP Quadra, and select modules of the 2600 as well. The ProSoloist model is finished (has been for a long time), the Quadra and 2600 models are in the prototyping/beta stage. There will be a website with full descriptions and sound samples, but I'd like to finish the modelling work before I launch the website.

 

As Alan mentioned, I'm working on a Hammond Spinet project too, the reason being that I recently picked up a nearly mint L122 to complement the T200 that I've had for years. My little workshop is now crowded with Hammond parts and stuff, which is why I decided to model the Hammonds so that I can then put them into storage until I find a better place for them.

 

Why model the spinets? Well, the B3 and other consoles are fantastic instruments, but I always felt there was a place for the spinets too. They have their own sound and feel.

 

In all tonewheel Hammonds, the tonewheel generator, key contacts/busbars and drawbar circuits form an extremely complex mesh where signal sources and loads interact, resulting in subtle compression and tonal variation. The thing is that in the spinets, the darker tone has a tendency to bring out the complex tonal transients that occur at key-on and key-off, whereas in the consoles this body of sound is often masked by the loud key click. Key click is nice for blues/jazz licks, but for certain chordal or cathedral inspired music I prefer the more subtle tone of the spinets.

 

The spinets have their differences too. For instance, the L-series has the special vibrato amp which provides a little static phase shift even when switched off. This, weirdly enough, affects the percussion tone through partial phase cancellation. The T-series has the odd percussion voicings along with some rather unexpected compression mechanisms. The M-series is probably closest to the consoles in terms of features and sound purity (only a handful of tubes in the signal path). All I can say is the modelling project has been very enlightening. I now know, at least in part, why these are so wonderfully playable instruments.

 

Well, not long back I suggested JoJoB3 should start this new thread for his Soloist project, and now I've gone and hijacked it talking about Hammonds. So much for consistency!

 

Regards,

-joachim

 

[jverghese]

I must ask, since we have mr Verghese in this thread - is the ProSoloist Rack still being made?

Yes, I currently have materials for a number of units, please contact me privately for more info. Thanks -joachim

[JoJoB3]

Yes, but i don't care. This is awesome (I wanna try that pro soloist).

 

Still no luck on finding conductive foam.

Then again...is it really necessary? (isn't it to buffer the "meeting of metal" for the triggering ?)

 

Hi,

 

Thanks for all the kind words, Alan, much appreciated.

 

My visits here are rather sporadic (as you should be able to tell by now). I would love to contribute more often, but simply don't have the time. I felt obliged to respond to JoJoB3's request for help with his ARP Soloist, it's such a great thing that people still want to keep those things alive -- and make great music with them too.

 

As for my ProSoloist+ rack project, it's still a work in progress. As you may know, it will include models of not only the ProSoloist, but the lead section of the ARP Quadra, and select modules of the 2600 as well. The ProSoloist model is finished (has been for a long time), the Quadra and 2600 models are in the prototyping/beta stage. There will be a website with full descriptions and sound samples, but I'd like to finish the modelling work before I launch the website.

 

As Alan mentioned, I'm working on a Hammond Spinet project too, the reason being that I recently picked up a nearly mint L122 to complement the T200 that I've had for years. My little workshop is now crowded with Hammond parts and stuff, which is why I decided to model the Hammonds so that I can then put them into storage until I find a better place for them.

 

Why model the spinets? Well, the B3 and other consoles are fantastic instruments, but I always felt there was a place for the spinets too. They have their own sound and feel.

 

In all tonewheel Hammonds, the tonewheel generator, key contacts/busbars and drawbar circuits form an extremely complex mesh where signal sources and loads interact, resulting in subtle compression and tonal variation. The thing is that in the spinets, the darker tone has a tendency to bring out the complex tonal transients that occur at key-on and key-off, whereas in the consoles this body of sound is often masked by the loud key click. Key click is nice for blues/jazz licks, but for certain chordal or cathedral inspired music I prefer the more subtle tone of the spinets.

 

The spinets have their differences too. For instance, the L-series has the special vibrato amp which provides a little static phase shift even when switched off. This, weirdly enough, affects the percussion tone through partial phase cancellation. The T-series has the odd percussion voicings along with some rather unexpected compression mechanisms. The M-series is probably closest to the consoles in terms of features and sound purity (only a handful of tubes in the signal path). All I can say is the modelling project has been very enlightening. I now know, at least in part, why these are so wonderfully playable instruments.

 

Well, not long back I suggested JoJoB3 should start this new thread for his Soloist project, and now I've gone and hijacked it talking about Hammonds. So much for consistency!

 

Regards,

-joachim

[KeysBR]

As Alan mentioned, I'm working on a Hammond Spinet project too, the reason being that I recently picked up a nearly mint L122 to complement the T200 that I've had for years. My little workshop is now crowded with Hammond parts and stuff, which is why I decided to model the Hammonds so that I can then put them into storage until I find a better place for them.

 

This news left me drooling. As a T400 owner (and in a Brazilian Genesis cover band), I'm constantly frustrated that there are no clonewheels out there sounding like a spinet, it is a great sound, very rock and roll.

 

(Joachim, I left you a PM.)

[JoJoB3]

Just wanted to update that the "4027-1" (remake or orig) DOES NOT work in the early ARP soloist/2700 (pre "pro-soloist"). I bought one from the UK and had it installed - it does not work. Only works for ARP 2600 and like.

 

If anyone might know exactly "why" it does not work with this synth I'd love to know btw.

 

The only recourse was to try and pick away the black epoxy on the original 4027 (not 4027-1) and repair. My tech is awesome and did just that. Back to happiness (but for how long?? cue the organ stinger)

 

I have a 4027-1 if anyone needs one btw.