Roland - AP-7 Jet Phaser  [schematic]

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

Re: Roland - AP-7 Phaser

Postby RWalleyTX » 07 Jan 2018, 08:36

Posts: 1
Joined: 07 Jan 2018, 07:51
Has thanked: 0 time
Have thanks: 0 time

Re: Roland - AP-7 Jet Phaser

Postby nechelovechek » 12 Feb 2019, 21:22

Hi. Greetings from Russia. Its a great forum you have there.
I've tried to build that phaser for a long time. It works now somehow, but the output of the effect is very low. Amplitude of the output is 4 times smaller then input. What might be tweaked to make it sound louder? I've used shematics in the attachment.
You do not have the required permissions to view the files attached to this post.
Posts: 1
Joined: 12 Feb 2019, 21:06
Has thanked: 0 time
Have thanks: 0 time

Re: Roland - AP-7 Jet Phaser

Postby Fender3D » 12 Feb 2019, 23:33

Hi and welcome to the forum,

you're asking what to tweak to make it sound louder.... well actually, the phaser part has a low input impedance, then, if you're connecting it to a high impedance source, like guitar or bass, it should "dull" your sound with a slight volume loss. I'd add a small buffer (just a FET or BJT stage) in front of it.

IC3b and IC1d have a gain ~3 which should recover any loss in the passive output mixer...
So I would say: there's nothing to tweak... check for resistors values, solder joints or eventual short or track cut (assuming your PCB is correct...)
User avatar
Cap Cooler
Posts: 506
Joined: 08 Aug 2009, 03:40
Location: Helltaly
Has thanked: 97 times
Have thanks: 131 times


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

Who is online

Users browsing this forum: Disco_Gee, Google [Bot], vic, zamguitar and 5 guests