Author Topic: Roland Jet Phaser!  (Read 2271 times)

danfrank

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Roland Jet Phaser!
« on: November 22, 2020, 03:30:28 PM »
Ok, I'm not joking this time, this needs to be done! I'm sure JimiLee will back me up on this... Warm Audio just released an authentic remake so unobtanium parts is no longer an excuse!
This would be a great project... Able to fit in a 1590BB would make it double nice.
Any takers?
Lol!

Betty Wont

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Re: Roland Jet Phaser!
« Reply #1 on: November 22, 2020, 04:06:05 PM »
I'm in!!

jimilee

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Re: Roland Jet Phaser!
« Reply #2 on: November 22, 2020, 04:52:17 PM »
Daaaamn, sounds awesome.


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Pedal building is like the opposite of sex.  All the fun stuff happens before you get in the box.

aion

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Re: Roland Jet Phaser!
« Reply #3 on: November 23, 2020, 08:07:45 AM »
I've got one in the works. It'll be 1790NS/1590XX though, 1590BB is a little too masochistic and would be a much more difficult build.

danfrank

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Re: Roland Jet Phaser!
« Reply #4 on: November 23, 2020, 04:00:42 PM »
Nice, Great to hear!
Do you have an approximate ETA?
Thanks

aion

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Re: Roland Jet Phaser!
« Reply #5 on: November 23, 2020, 04:30:59 PM »
Maybe spring or summer... itís about half designed, but Iím working through options for offering matched JFETs along with it and thatís the main delay. Donít want to put it out there if itís near impossible to actually build!

madbean

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Re: Roland Jet Phaser!
« Reply #6 on: November 23, 2020, 10:40:38 PM »
That is killer. Looking forward to building one.

danfrank

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Re: Roland Jet Phaser!
« Reply #7 on: December 01, 2020, 12:26:11 AM »
Maybe spring or summer... itís about half designed, but Iím working through options for offering matched JFETs along with it and thatís the main delay. Donít want to put it out there if itís near impossible to actually build!

Can you give info as to what FETs work well with this? Will your standard matched phaser FETs work or do they need to be a special type? I know there's 8 of them doing the deed.... The original 2SK30s haven't been made in a long time, audiophiles liked using them before they got scarce.

Thewintersoldier

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Re: Roland Jet Phaser!
« Reply #8 on: December 01, 2020, 09:14:42 AM »
this is gonna be a fun build, can't wait Kevin!
Who the hell is Bucky?

aion

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Re: Roland Jet Phaser!
« Reply #9 on: December 01, 2020, 09:42:29 AM »
Maybe spring or summer... itís about half designed, but Iím working through options for offering matched JFETs along with it and thatís the main delay. Donít want to put it out there if itís near impossible to actually build!

Can you give info as to what FETs work well with this? Will your standard matched phaser FETs work or do they need to be a special type? I know there's 8 of them doing the deed.... The original 2SK30s haven't been made in a long time, audiophiles liked using them before they got scarce.

That's part of the research I still need to do. Lots of people have tried and failed to make a DIY version, so I think the FETs are important and need to meet certain specs that are different than the standard Phase 90 matched set. They seem to be lower in Vgs(10k) in general but I don't know if that's the full story.

I have two original units on the bench for dissecting, so I'm confident I'll be able to crack it, but just not sure yet what I'll find out.

aion

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Re: Roland Jet Phaser!
« Reply #10 on: January 12, 2021, 11:44:21 AM »


Went on a bit of a tear the past few days and came out the other side with this.

I ended up tricking it out pretty thoroughly, which was fun. The rotary switch on the original is nice from an aesthetic perspective, preserving the simple control layout, but it hides some parameters such as jet tone and phaser depth/intensity that are set with fixed resistors and switches instead of knobs.

So we end up with these extra features -
  • Jet (the distortion circuit before the phaser) is independently footswitchable
  • Full tone control added to Jet mode (the original just has 2 modes, full CW for treble or full CCW for bass on a Big Muff tone stack)
  • Distortion can be dialed back (full-up is equivalent to stock) - which should allow for some semi-clean boost to fix volume issues, as well as less fuzzy drive tones
  • Depth control added (original rotary control just had two depth presets)
  • Fast speed added (on the original, Fast mode is a preset speed and only Slow mode is adjustable)
  • Toggle switch for phase stages (4/6/8, with 8 being the stock mode)
  • Input buffer added from 1976 revision (most DIY attempts have not included this buffer, which Roland added less than a year after production started in 1975 due to reported volume issues) - the buffer always comes before the effect, but there's an internal slide switch allowing bypass mode to be either true bypass or buffered
  • Charge pump inverter for +/-9V (the original required 2 batteries and had no external power jack)
So the end result is that it's still electrically 100% identical to the original Jet Phaser, but a lot more flexible.

I'm only just sending it off to prototyping today, so it'll be several weeks/months before it sees the light of day (and that's assuming it works... lol) - but just to prime any appetites, a significant milestone has been hit :)

Time to dust off those JFET matching rigs...
« Last Edit: January 12, 2021, 12:44:45 PM by aion »

Betty Wont

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Re: Roland Jet Phaser!
« Reply #11 on: January 12, 2021, 12:08:58 PM »
oh my......!!!! fantastic!!! best of luck on the proto, I'll be watching this one.

gordo

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Re: Roland Jet Phaser!
« Reply #12 on: January 12, 2021, 01:18:19 PM »
That is sick.  I must admit that my recollection of the original was that it was a one trick pony (although a fun one).  This looks like it will be just short of completely insane.  Really looking forward to it.
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jimilee

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Re: Roland Jet Phaser!
« Reply #13 on: January 12, 2021, 01:33:43 PM »
Jeeeeesus; Iím all in.


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Pedal building is like the opposite of sex.  All the fun stuff happens before you get in the box.

danfrank

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Re: Roland Jet Phaser!
« Reply #14 on: January 12, 2021, 05:23:13 PM »
Thanks for the update and (2x) thanks for working on this! I'm really looking forward to this project. I love the name!


BTW, I just finished the 2 Blueshift boards and I plan to use them in a PA with 4 (QUAD!) Gromes G-101 100 watt tube amps for super-wide stereo. I was wondering how to make a 2 channel system into 4 and the 2 Blueshifts I have will work perfectly.
Thanks again...
« Last Edit: January 12, 2021, 05:26:23 PM by danfrank »