Roland Jet Phase incoming!
- chicago_mike
- Tube Twister
I have a Roland JetPhase AP-7 coming in the mail today. Does anybody need any measurements or anything from it?
Skyline FX 2013
- aion
- Solder Soldier
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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
- modman
- a d m i n
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We have a thread on the Roland Jet Phaser here: https://www.freestompboxes.org/viewtopic.php?f=1&t=589
Links to service notes etc...most of the links to guts are dead though...
Links to service notes etc...most of the links to guts are dead though...
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal
- chicago_mike
- Tube Twister
Im cool with helping out!! Whats the easiest way to measure the fets ?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 commonlike 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.
Skyline FX 2013
- aion
- Solder Soldier
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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)
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)
- chicago_mike
- Tube Twister
Cool.
I should test ALL fets in the phase section yes? Not just like 2 - 4 ?
I should test ALL fets in the phase section yes? Not just like 2 - 4 ?
Skyline FX 2013
- aion
- Solder Soldier
Information
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.chicago_mike wrote:I should test ALL fets in the phase section yes? Not just like 2 - 4 ?
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.
- chicago_mike
- Tube Twister
breadboarding an Arduino fet tester for this. Should have the jets testedasap!
Skyline FX 2013
- aion
- Solder Soldier
Information
Oh awesome! Which one is it?chicago_mike wrote:breadboarding an Arduino fet tester for this. Should have the jets testedasap!
- chicago_mike
- Tube Twister
this one:
https://create.arduino.cc/projecthub/pl ... ter-dbafb4
I didnt really know there were others
https://create.arduino.cc/projecthub/pl ... ter-dbafb4
I didnt really know there were others
Skyline FX 2013
- chicago_mike
- Tube Twister
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
When I get more time, I take measurements of the other fets
Skyline FX 2013