XITE-1 preamps

The Sonic Core XITE hardware platform for Scope
User avatar
krizrox
Posts: 1311
Joined: Tue Aug 21, 2001 4:00 pm
Location: Elgin, IL USA
Contact:

XITE-1 preamps

Post by krizrox » Wed Nov 11, 2015 12:02 pm

I can't tell if this is something new or has been like this since I bought my unit last year. I admittedly haven't used the two front panel mic preamps much. But I was playing around with them a lot more the past few days and noticed a weird... thing

If I increase the input gain control slowly from dead zero (about 7 oclock) I see no signal activity in my Scope/DAW input meters until I get to roughly 8 or 8:30 on the dial and then the signal pops in abruptly. It doesn't fade in gradually like you'd expect. Both channels do the same thing. Same thing if I fade out. The input signal seems to drop out completely at around 8 or 8:30.

Can anyone confirm if this is normal behavior or possibly a problem? After the signal kicks in the gain adjust seems to work as expected.

thanks!

User avatar
garyb
Posts: 21183
Joined: Sun Apr 15, 2001 4:00 pm
Location: ghetto by the sea

Re: XITE-1 preamps

Post by garyb » Wed Nov 11, 2015 12:16 pm

i'd say that it's just the taper of the pots.

User avatar
Bud Weiser
Posts: 1304
Joined: Tue Sep 14, 2010 5:29 am

Re: XITE-1 preamps

Post by Bud Weiser » Wed Nov 11, 2015 12:42 pm

krizrox wrote:I can't tell if this is something new or has been like this since I bought my unit last year. I admittedly haven't used the two front panel mic preamps much. But I was playing around with them a lot more the past few days and noticed a weird... thing

If I increase the input gain control slowly from dead zero (about 7 oclock) I see no signal activity in my Scope/DAW input meters until I get to roughly 8 or 8:30 on the dial and then the signal pops in abruptly. It doesn't fade in gradually like you'd expect. Both channels do the same thing. Same thing if I fade out. The input signal seems to drop out completely at around 8 or 8:30.

Can anyone confirm if this is normal behavior or possibly a problem? After the signal kicks in the gain adjust seems to work as expected.

thanks!
Yes, it´s, the same w/ my XITE-1 and I had the same question long time ago and after I had received my XITE.
Like you, I didn´t use the mic/DI section for a long time until I connected a stereo line output instrument using the pad switches.
I was really irritated when the signals popped in abruptly and the same way on both channels.
In fact, it behaved like switches not pots and going above the level where signal kicked in, it already distorted w/ a line level signal connected.

Got no answer though and now I´m happy you´re the next one coming up w/ that issue.

Never tried a mic up to now ...
Does it happen w/ mics too or does it happen only when pad switches are activated ?

Bud

User avatar
garyb
Posts: 21183
Joined: Sun Apr 15, 2001 4:00 pm
Location: ghetto by the sea

Re: XITE-1 preamps

Post by garyb » Wed Nov 11, 2015 12:44 pm

log taper pots.
they come on quickly at the end of their travel.

User avatar
Bud Weiser
Posts: 1304
Joined: Tue Sep 14, 2010 5:29 am

Re: XITE-1 preamps

Post by Bud Weiser » Wed Nov 11, 2015 12:44 pm

garyb wrote:i'd say that it's just the taper of the pots.
:D

You say there are the wrong pots in the circuitry ?

Bud

User avatar
garyb
Posts: 21183
Joined: Sun Apr 15, 2001 4:00 pm
Location: ghetto by the sea

Re: XITE-1 preamps

Post by garyb » Wed Nov 11, 2015 12:46 pm

no.
log and audio taper pots are quite common.

User avatar
Bud Weiser
Posts: 1304
Joined: Tue Sep 14, 2010 5:29 am

Re: XITE-1 preamps

Post by Bud Weiser » Wed Nov 11, 2015 12:49 pm

garyb wrote:log taper pots.
they come on quickly at the end of their travel.
These come quickly at the beginning of their travel.
08:30 - 09:00h is about beginning of travel to me.

Bud

User avatar
garyb
Posts: 21183
Joined: Sun Apr 15, 2001 4:00 pm
Location: ghetto by the sea

Re: XITE-1 preamps

Post by garyb » Wed Nov 11, 2015 12:54 pm

well, then change them to something that suits you.

there are three main kinds.
linear
logarithmic
anti-logarithmic

http://www.resistorguide.com/potentiometer-taper/

User avatar
krizrox
Posts: 1311
Joined: Tue Aug 21, 2001 4:00 pm
Location: Elgin, IL USA
Contact:

Re: XITE-1 preamps

Post by krizrox » Wed Nov 11, 2015 1:24 pm

Change them to something that suits you? lol

That's a strange answer.

At least I know it's not a defect related to my unit. I was recording a miked up guitar amp set to very a reasonable volume level. The input gain went from nothing, to something, to insane distorted signal in no time. I've never seen behavior like this before from a mic preamp.

User avatar
tlaskows
Posts: 1536
Joined: Fri May 20, 2005 4:00 pm
Location: Ontario, Canada
Contact:

Re: XITE-1 preamps

Post by tlaskows » Wed Nov 11, 2015 3:24 pm

I've used all the pots except anti-logarithmic. That's a new one for me :D

-Tom

User avatar
Bud Weiser
Posts: 1304
Joined: Tue Sep 14, 2010 5:29 am

Re: XITE-1 preamps

Post by Bud Weiser » Wed Nov 11, 2015 4:12 pm

krizrox wrote:Change them to something that suits you? lol

That's a strange answer.
indeed ...
krizrox wrote: At least I know it's not a defect related to my unit. I was recording a miked up guitar amp set to very a reasonable volume level. The input gain went from nothing, to something, to insane distorted signal in no time. I've never seen behavior like this before from a mic preamp.
And I now know it happens w/ mics connected and padswitches unused also.
When that isn´t normal behaviour, I now wonder why never ever anyone recognized that issue.

Bud

User avatar
Bud Weiser
Posts: 1304
Joined: Tue Sep 14, 2010 5:29 am

Re: XITE-1 preamps

Post by Bud Weiser » Wed Nov 11, 2015 4:21 pm

garyb wrote:well, then change them to something that suits you.
:lol:
garyb wrote: there are three main kinds.
linear
logarithmic
anti-logarithmic

http://www.resistorguide.com/potentiometer-taper/
Thx, I know what (audio-) taper is.
My XITE-1 is out of warranty now,- but when I came up w/ the question here it wasn´t. S##t !

I never looked inside the XITE-1.
Is the mic/DI section a separate circuit board where the pots are attached to w/ easy to solder soldering lugs ?

When it´s all the SMD technology/soldering I´d have no chance exchanging parts myself.

Can you tell me the resistance of the pots used ? 10K, 25k or 50 or what ?

Can you provide a service manual ?

:roll:

Bud

User avatar
garyb
Posts: 21183
Joined: Sun Apr 15, 2001 4:00 pm
Location: ghetto by the sea

Re: XITE-1 preamps

Post by garyb » Wed Nov 11, 2015 4:46 pm

no, i don't have a service manual.
yes, the pots are on a separate board, afair.
no, i don't know the values, but they're printed on the pots.

User avatar
tlaskows
Posts: 1536
Joined: Fri May 20, 2005 4:00 pm
Location: Ontario, Canada
Contact:

Re: XITE-1 preamps

Post by tlaskows » Wed Nov 11, 2015 4:50 pm

Yes, they're always printed and you can just measure across the leads...

-Tom

User avatar
krizrox
Posts: 1311
Joined: Tue Aug 21, 2001 4:00 pm
Location: Elgin, IL USA
Contact:

Re: XITE-1 preamps

Post by krizrox » Sun Jan 03, 2016 8:24 am

My unit is probably out of warranty by now. Have never opened it up to look inside. These days... those components are all SMD mounted which makes them virtually impossible to remove or replace without very sophisticated tools. My A16 is like that. No hope of anything field repairable. And sending stuff to Germany for repair means 2 months without the gear.

I've been thinking about this since I posted the original message (I haven't been thinking about it a lot lol) and haven't convinced myself it's necessary to go through what I envision will be a painful and potentially risky upgrade just to solve a minor problem. I don't think I would ever be adjusting them on and off during normal tracking so I can live with them the way they are.

User avatar
tlaskows
Posts: 1536
Joined: Fri May 20, 2005 4:00 pm
Location: Ontario, Canada
Contact:

Re: XITE-1 preamps

Post by tlaskows » Sun Jan 03, 2016 11:33 am

I wouldn't recommend opening it up if you don't have experience. I've desoldered SMT 144 pin chips with little spacing before and replaced them. It's not that easy at first. If you're talking about the pots, they are not usually surface mounted. Old ones are just hooked up with wire, the never ones are thru hole. I like using the good old ones for my builds.

-Tom

User avatar
Bud Weiser
Posts: 1304
Joined: Tue Sep 14, 2010 5:29 am

Re: XITE-1 preamps

Post by Bud Weiser » Mon Jan 04, 2016 2:27 pm

krizrox wrote:My unit is probably out of warranty by now. Have never opened it up to look inside. These days... those components are all SMD mounted which makes them virtually impossible to remove or replace without very sophisticated tools. My A16 is like that. No hope of anything field repairable. And sending stuff to Germany for repair means 2 months without the gear.
HNY !

I´m just returned from home ...
I agree !
I´d never open XITE-1 myself just only to replace 2 pots.
krizrox wrote: I don't think I would ever be adjusting them on and off during normal tracking so I can live with them the way they are.
Well,- "the way they are" is weird, it´s not common behaviour.
I wonder why we 2 users are the only ones complaining on that issue.
How many XITE users are out there and is it really true only our 2 XITE boxes show that behaviour ?
If yes, why in the world there aren´t any more comments on the issue like "we don´t have it, it´s malfunction of your box only".

In fact, I don´t know how to replace these pots when there are no schematics and specs available.
Reading the specs printed on these pots is worthless because they don´t work as expected.
I also wonder why manufacturers of XITE-1 don´t know the issue.
Who does the quality tests for the box and didn´t they test functionality of preamps ?

Bud

jksuperstar
Posts: 1475
Joined: Mon Nov 15, 2010 12:57 pm

Re: XITE-1 preamps

Post by jksuperstar » Mon Jan 04, 2016 3:10 pm

I see something similar on my XITE. But I only use the preamps for mics and hi-z instruments, not line level, and have never had an issue with Gain or not having enough overhead (even with an active bass), so I never thought of it as a problem.

User avatar
krizrox
Posts: 1311
Joined: Tue Aug 21, 2001 4:00 pm
Location: Elgin, IL USA
Contact:

Re: XITE-1 preamps

Post by krizrox » Fri Jan 08, 2016 5:48 am

Bud Weiser wrote:
Well,- "the way they are" is weird, it´s not common behaviour.
I wonder why we 2 users are the only ones complaining on that issue.
How many XITE users are out there and is it really true only our 2 XITE boxes show that behaviour ?
If yes, why in the world there aren´t any more comments on the issue like "we don´t have it, it´s malfunction of your box only".


Bud

We'll probably never know the answer to those questions. I'm sure there are a fair number of Xite users out there. Some percentage probably have never used the mic preamps. Some percentage have never been to PlanetZ. Some percentage just plain weren't paying attention. That leaves us lol

User avatar
Bud Weiser
Posts: 1304
Joined: Tue Sep 14, 2010 5:29 am

Re: XITE-1 preamps

Post by Bud Weiser » Fri Jan 08, 2016 7:42 am

krizrox wrote: We'll probably never know the answer to those questions. I'm sure there are a fair number of Xite users out there. Some percentage probably have never used the mic preamps. Some percentage have never been to PlanetZ. Some percentage just plain weren't paying attention. That leaves us lol
Well, we could probably find a tech modding the Mic/DI section circuit board, or if modding is not necessary, just only replace pots.
But as long as there are no schematics and specs available, it would be really hard to find the right parts.

It´s all matter of what the electronic circuitry expects to see as the correct pot and to work perfect.

I wonder if there is a hardware design flaw which isn´t fixable because it´s related to other components, circuit layout or such or if the manufacturer simply used wrong pots.
These were 2 different issues and had to be investigated 1st.

Or,- is the hardware perfect and the firmware causes the issue ?

I´d find it pretty stupid, opening the box and look for the pot´s specs, then buy others as replacements and before it´s not clear what the fault really is.

In fact the actual pot works like a switch.
You feed a signal into the preamp, turn the pot up to somewhere between 8-9:00h and then see the signal and hear it.
When you go higher it distorts.
That´s not what a pot normally does and it´s also not what I know from differences of linear or logarithmic behaviour.

Bud

Post Reply