EHX - Mini Q-Tron  [schematic]

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
User avatar
modman
a d m i n
Information
Posts: 4890
Joined: 19 Jun 2007, 16:57
Has thanked: 4394 times
Been thanked: 2131 times

Post by modman »

click for a larger pic
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal

User avatar
Bernardduur
Transistor Tuner
Information
Posts: 1218
Joined: 24 Aug 2007, 07:36
my favorite amplifier: Welagen - ODR
Location: Losser.........
Has thanked: 94 times
Been thanked: 732 times

Post by Bernardduur »

I've already traced that unit

Will search
'No more....... loud music.......'
Follow my love for pedals and amps on https://bernardduur.blogspot.com and https://www.instagram.com/bernardduur1

User avatar
Dirk_Hendrik
Old Solderhand
Information
Posts: 4193
Joined: 03 Jul 2007, 08:44
Location: Old Amsterdam
Has thanked: 232 times
Been thanked: 887 times
Contact:

Post by Dirk_Hendrik »

Don't bother. It's in the big EH archive that was to fe found online untill the Ork came by.

As said, PM me with a mailadress if you need something from that archive.
Sorry. Plain out of planes.

http://www.dirk-hendrik.com

User avatar
bajaman
Old Solderhand
Information
Posts: 4549
Joined: 26 Jun 2007, 21:18
Location: New Brighton, Christchurch, NZ
Has thanked: 595 times
Been thanked: 2056 times

Post by bajaman »

I had one in for servicing recently - took some high res pictures of the solder side etc. - anyone want to build one - I have the artwork almost cloned - 75% done. :lol: :wink:
bajaman

User avatar
Bernardduur
Transistor Tuner
Information
Posts: 1218
Joined: 24 Aug 2007, 07:36
my favorite amplifier: Welagen - ODR
Location: Losser.........
Has thanked: 94 times
Been thanked: 732 times

Post by Bernardduur »

Dirk_Hendrik wrote:Don't bother. It's in the big EH archive that was to fe found online untill the Ork came by.

As said, PM me with a mailadress if you need something from that archive.
K, I won't post it :)
'No more....... loud music.......'
Follow my love for pedals and amps on https://bernardduur.blogspot.com and https://www.instagram.com/bernardduur1

User avatar
lohstah
Solder Soldier
Information
Posts: 237
Joined: 08 Jul 2007, 20:08
Has thanked: 214 times
Been thanked: 96 times

Post by lohstah »

i borrowed a very early unit from my music store when they had just come out and it had the hp and lp the wrong way round, so hp was really lp and vice versa. is it still that way ?

cheers,
lohstah

User avatar
Bernardduur
Transistor Tuner
Information
Posts: 1218
Joined: 24 Aug 2007, 07:36
my favorite amplifier: Welagen - ODR
Location: Losser.........
Has thanked: 94 times
Been thanked: 732 times

Post by Bernardduur »

lohstah wrote:i borrowed a very early unit from my music store when they had just come out and it had the hp and lp the wrong way round, so hp was really lp and vice versa. is it still that way ?

cheers,
lohstah
No; all units I had in were in the right order
'No more....... loud music.......'
Follow my love for pedals and amps on https://bernardduur.blogspot.com and https://www.instagram.com/bernardduur1

User avatar
modman
a d m i n
Information
Posts: 4890
Joined: 19 Jun 2007, 16:57
Has thanked: 4394 times
Been thanked: 2131 times

Post by modman »

Thanks guys!

I got it in a trade for a DIY TS. Just took these pics as I had to dissemble it anyway. I'll show you why:

Image

After a trip on acetone yesternight, I got it back to this now:

Image

Also put the knobs in some acetone -- they didn't take it so well, they started dissolving. :slap:

With regard to the EH archive, Meanderthal did us a favour in the POG thread. Everybody could contribute by taking the zip and uploading it to different free hosting services. Or maybe we should find some Japanese free upload site, perhaps it'll last longer when hosted there.

The Qtron (not micro or mini Qtron) schematic in that collection shows 4558 opamps where mine has TLC2262CP, and gets fed 18V to pin 87 of the first IC. Mine just runs off 9V
bajaman wrote:I had one in for servicing recently - took some high res pictures of the solder side etc. - anyone want to build one - I have the artwork almost cloned - 75% done. :lol: :wink:
bajaman
:shock: :D Baja, you must be clairvoyant!
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal

User avatar
bajaman
Old Solderhand
Information
Posts: 4549
Joined: 26 Jun 2007, 21:18
Location: New Brighton, Christchurch, NZ
Has thanked: 595 times
Been thanked: 2056 times

Post by bajaman »

Okay Modman - as you already have the enclosure and we all have the mini Qtron schematic, I will have the artwork completed for the coming weekend :wink:
cheers
bajaman

User avatar
modman
a d m i n
Information
Posts: 4890
Joined: 19 Jun 2007, 16:57
Has thanked: 4394 times
Been thanked: 2131 times

Post by modman »

Bajaman, there is no hurry at all, just let me know when you get round to it. I should first try how it sounds *without the artwork* :D
Being a funk junk, I cannot see how I could ever do without this pedal.
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal

User avatar
lohstah
Solder Soldier
Information
Posts: 237
Joined: 08 Jul 2007, 20:08
Has thanked: 214 times
Been thanked: 96 times

Post by lohstah »

aarrrghh! of course i meant the micro q-tron with my post about the wrong lettering...

User avatar
bajaman
Old Solderhand
Information
Posts: 4549
Joined: 26 Jun 2007, 21:18
Location: New Brighton, Christchurch, NZ
Has thanked: 595 times
Been thanked: 2056 times

Post by bajaman »


User avatar
polarbearfx
Resistor Ronker
Information
Posts: 310
Joined: 27 Sep 2007, 11:14
Has thanked: 3 times
Been thanked: 2 times

Post by polarbearfx »

Is this thing worth building? I love the bigger qtron. Some of the components look pretty hard to find. I guess a diy version might be hip.

User avatar
modman
a d m i n
Information
Posts: 4890
Joined: 19 Jun 2007, 16:57
Has thanked: 4394 times
Been thanked: 2131 times

Post by modman »

Great stuff, Baja, incredible. Do you know of any available verified MiniQtron schematics? Have been searching but didn't find any. If we do, this could go into the projects folder.

thanks!
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal

User avatar
bajaman
Old Solderhand
Information
Posts: 4549
Joined: 26 Jun 2007, 21:18
Location: New Brighton, Christchurch, NZ
Has thanked: 595 times
Been thanked: 2056 times

Post by bajaman »

Hi modman
i have the factory schematic - it was in the archive that AG discovered - let me know if you have not got it and i will email it to you
cheers
bajaman

User avatar
Nikifena
Solder Soldier
Information
Posts: 183
Joined: 04 Oct 2007, 06:12
Location: Bulgaria
Has thanked: 3 times
Been thanked: 39 times

Post by Nikifena »

Thanks banja.

User avatar
floris
Cap Cooler
Information
Posts: 473
Joined: 14 Oct 2007, 12:05
Has thanked: 231 times
Been thanked: 72 times

Post by floris »

Sorry to bother you but I'm looking for schematics of the EH mini QTron (perhaps also a regular QTron if you have it).
I've looked for it on freestompboxes, diystompboxes and some googling but can not find it.
I have a mini QTron and want to add a control to adjust the attack of the envelope follower section.
I did find and download some PCB and Layout from bajaman, thanks!

I saw some reference to a site containing all factory EH schematics but that one is down, probably just too good to be true. Can somebody post, host that zip file containing all those schematics? Would be much appreciated.

Floris.

User avatar
RLBJR65
Resistor Ronker
Information
Posts: 280
Joined: 30 Jun 2007, 16:07
Location: USA
Been thanked: 3 times
Contact:

Post by RLBJR65 »

Qtron, MiniQtron and much much more :D

(file down)
Last edited by modman on 25 Apr 2008, 18:42, edited 1 time in total.
Reason: admin: removed dead link, check below

User avatar
floris
Cap Cooler
Information
Posts: 473
Joined: 14 Oct 2007, 12:05
Has thanked: 231 times
Been thanked: 72 times

Post by floris »

The file has been removed! :cry:
"An error has occured:
This file has been deleted.
Reason: THIS FILE IS FORBIDDEN TO BE SHARED! Complaints received."
Can somebody re-post / re-host it please?

Flo.

User avatar
oscarv77
Solder Soldier
Information
Posts: 181
Joined: 25 Aug 2007, 01:41
Has thanked: 11 times
Been thanked: 11 times

Post by oscarv77 »


Post Reply