Deacy build thread.

  • Thread starter Thread starter Steenamaroo
  • Start date Start date
Abandon ship.....

Threw the head up and just decided to have an amp and a pedal, like Rich.

I really liked the idea of 1 power supply and one studio box, but screw it; If it's going to be this much hassle, I'm not that botered!!! :p

So, TB is removed and everything is working perfectly.

Just need a little box. :)
 
Fair call! Sometimes life is too short :thumbs up:

Now, some more sounds, please!
 
Interesting update for anyone who is following.

I've just discovered that with guitar straight into Deacy, my gtr tone controls don't work!
I wonder if this indicates some underlying issue that's been the root of my problems?

It's a les paul with 50s wiring, so the tone is just a cap to ground through a pot.

The tone knob does nothing until I get right to the off position, at which point my tone actually becomes a little fizzier!

Mean anything to you, Paul?
 
The tone knob does nothing until I get right to the off position, at which point my tone actually becomes a little fizzier!

Mean anything to you, Paul?

Nah! Maybe the guitar does not like the input impedance in the deacy?
 
Perhaps you're right.

Tone controls work with the treble booster in the path, so I guess that would make sense?
 
Yes. I looks to me like the input impedance on the deacy is low?. If you wanted to drive the deacy without the treble boost, you could build a simple and cheap buffer which will have high input impedance and will happily drive the following load.

I did a quick google. A FET or opamp buffer as found here: Guitar Buffer Circuits would probably do the trick.
 
Hmm. I'll ask Kip if his is the same.

I'm hoping that the amp has low input impedance through something that I've done wrong, rather than by design.

Thanks for the info.
 
I've just read that the original deacy had an input impedance of about 12kohm - way too low a load for a guitar pickup . It seems reasonable to assume that the deacy replicas have been similarly designed. That would make it pretty much obligatory to drive the deacy with something active - pedal, buffer, etc. You could confirm that with KAT.
 
Ok, fair enough. I've fired a message to Nigel.

I did notice that there are similar schematics knocking about, but the resistors at the input are often of higher values.
Perhaps some DIYers have compensated.
If it's like that by design I don't really mind.

Just FYI, I currently have the two devices powered by the inverter without issue. Don't ask me what I did, but it's working. :laughings:

Cheers again, Paul.
 
I'll check mine as soon as i get home.2.30pm and i'll report back.
I'm also intrested in what Nigel has to say.
I cant have a ciggy i quit. When the snooker on? :)
 
Cheers, kip.

IDK. We only get it on BBC here and apparently they don't tell you. :facepalm:
 
The tone pot is rendered practically useless.
You can tell a differance from completely on to completly off but its not as pronounced as normal and it seem worse with single coils too.
Any help?
 
Thanks kip.
Well, that answers that then.
It seems PR is right and the input impedance is low (by design).
I guess that's part of the reason for the TB in front of it, and kat do sell one.


Three main choices really.
Leave it alone.
Use a buffer or TB.
Modify the amp.

I don't even know if that last option is feasible, but I notice schematics floating around the web differ from KAT's kit.
The main differences are R1,R2,and r3. I'm intrigued to know if this is the reason.

It doesn't bother me that much now that I know it's not a fault.
Who knows, maybe I'll look at simple buffers some day.
 
I'll ask that belgian guy Rene and see what he says and ask if his build is differant to the KAT schematic.
 
I have emailed Rene and this is his response

Hi Rich,

Can you send me the KAT schematic so I can compare? I think your problem can have to do with the lower impediance of the amp, and that you are not using a treble booster. Normaly a treble booster is used before the amp and the treble booster has a high impediance and therefore not loading the guitar.

Best regards,
Gitaar in Tune



René
Always your guitar in Tune


needless to say i forwarded a copy of the KAT site Schematic. I await a response.
 
I think I've had a eureka moment!!!!!!!!

In the past I always had input+ and input shield travelling as a pair.

IE, the both go straight to the deacy, or they both go straight to the TB, through it, then on to the deacy.


IF......have a permanent input sheild straight to deacy and only switch the input+ between the two, everything is perfect.

Even the mild (acceptable) hum from my florescent lighting is gone!!!

I'm gona go build her back into the box to confirm.
 
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