Roland Jet Phase incoming!

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.

Roland Jet Phase incoming!

Postby chicago_mike » 07 Jun 2019, 18:01

I have a Roland JetPhase AP-7 coming in the mail today. Does anybody need any measurements or anything from it?
Skyline FX 2013
User avatar
chicago_mike
Tube Twister
 
Posts: 1760
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Have thanks: 302 times

Re: Roland Jet Phase incoming!

Postby aionios » 09 Aug 2019, 03:43

I would love to get the specs of the matched JFETs! Vgs(10k), Vgs(off) and Idss if you’re able. I’m curious to see how the voltages match up with something more common[list=][/list] like the Phase 90. I saw some taken from a unit awhile ago that were in the 0.7-0.8v range, which seemed really low to me - so I’m wondering if that was an anomaly or pretty standard.
Aion Electronics - DIY PCB projects for classic and obscure circuits
aionios
Breadboard Brother
 
Posts: 104
Joined: 22 Mar 2012, 01:12
Location: Des Moines, IA
Has thanked: 7 times
Have thanks: 138 times

Re: Roland Jet Phase incoming!

Postby modman » 09 Aug 2019, 10:32

We have a thread on the Roland Jet Phaser here: viewtopic.php?f=1&t=589
Links to service notes etc...most of the links to guts are dead though...
User avatar
modman
a d m i n
 
Posts: 4346
Joined: 19 Jun 2007, 17:57
Has thanked: 3283 times
Have thanks: 611 times

Re: Roland Jet Phase incoming!

Postby chicago_mike » 18 Aug 2019, 01:05

aionios wrote:I would love to get the specs of the matched JFETs! Vgs(10k), Vgs(off) and Idss if you’re able. I’m curious to see how the voltages match up with something more common[list=][/list] like the Phase 90. I saw some taken from a unit awhile ago that were in the 0.7-0.8v range, which seemed really low to me - so I’m wondering if that was an anomaly or pretty standard.


Im cool with helping out!! Whats the easiest way to measure the fets ?
Skyline FX 2013
User avatar
chicago_mike
Tube Twister
 
Posts: 1760
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Have thanks: 302 times

Re: Roland Jet Phase incoming!

Postby aionios » 18 Aug 2019, 14:19

The Vgs(10k) measurement is the most important one for phasers - there's a super simple circuit here that could be breadboarded:
http://www.geofex.com/article_folders/f ... tmatch.htm

Vgs(off) (which is basically the same as Vp) and Idss can be taken with another circuit:
http://tagboardeffects.blogspot.com/201 ... tcher.html
(The 2nd one on this page is much simpler and should work the same)
Aion Electronics - DIY PCB projects for classic and obscure circuits
aionios
Breadboard Brother
 
Posts: 104
Joined: 22 Mar 2012, 01:12
Location: Des Moines, IA
Has thanked: 7 times
Have thanks: 138 times

Re: Roland Jet Phase incoming!

Postby chicago_mike » 18 Aug 2019, 15:45

Cool.

I should test ALL fets in the phase section yes? Not just like 2 - 4 ?
Skyline FX 2013
User avatar
chicago_mike
Tube Twister
 
Posts: 1760
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Have thanks: 302 times

Re: Roland Jet Phase incoming!

Postby aionios » 18 Aug 2019, 19:37

chicago_mike wrote:I should test ALL fets in the phase section yes? Not just like 2 - 4 ?


Yep. An average Vgs is helpful, but also knowing the spread of lowest to highest, to know what Roland considered to be matched well enough for the circuit.

MXR was satisfied with up to 0.1V for the Phase 90, which is pretty wide, but matching 8 JFETs instead of 4 is even trickier so I’m curious if it’s tighter or broader than that.
Aion Electronics - DIY PCB projects for classic and obscure circuits
aionios
Breadboard Brother
 
Posts: 104
Joined: 22 Mar 2012, 01:12
Location: Des Moines, IA
Has thanked: 7 times
Have thanks: 138 times

Re: Roland Jet Phase incoming!

Postby chicago_mike » 22 Aug 2019, 17:09

breadboarding an Arduino fet tester for this. Should have the jets testedasap!
Skyline FX 2013
User avatar
chicago_mike
Tube Twister
 
Posts: 1760
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Have thanks: 302 times

Re: Roland Jet Phase incoming!

Postby aionios » 23 Aug 2019, 12:05

chicago_mike wrote:breadboarding an Arduino fet tester for this. Should have the jets testedasap!


Oh awesome! Which one is it?
Aion Electronics - DIY PCB projects for classic and obscure circuits
aionios
Breadboard Brother
 
Posts: 104
Joined: 22 Mar 2012, 01:12
Location: Des Moines, IA
Has thanked: 7 times
Have thanks: 138 times

Re: Roland Jet Phase incoming!

Postby chicago_mike » 23 Aug 2019, 23:53

this one:

https://create.arduino.cc/projecthub/pl ... ter-dbafb4


I didnt really know there were others :hmmm:
Skyline FX 2013
User avatar
chicago_mike
Tube Twister
 
Posts: 1760
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Have thanks: 302 times

Re: Roland Jet Phase incoming!

Postby chicago_mike » 03 Sep 2019, 19:20

Okay I posted my initial FET measurements. Only for the 8 phasing FETS right now.

When I get more time, I take measurements of the other fets
Skyline FX 2013
User avatar
chicago_mike
Tube Twister
 
Posts: 1760
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Have thanks: 302 times


Return to Modern Stompbox Effects (1975 - ...)

Who is online

Users browsing this forum: Google Feedfetcher and 14 guests