JFET Sunn Model T - noisy

[Isaiah]

Hello,

So, I breadboarded the first 2 gain stages of a Model T today.
That's three J201s or one and a half 12AX7s in the original circuit
(I skipped the EQ network and wired it straight to the Master volume control).

Anyhow, I got everything biased ok and it sounds pretty good (boosting it with an LPB-style circuit sounds ace!).
The problem is, it's really noisy.
Neither my guitar or bass are shielded, could that be the problem?
Or could it be that it's only on a breadboard?
I'm playing straight into an old Soundcraft Delta mixer (with external rackmount PSU), so maybe I could be picking up hum from that...

I know the circuit will amplify any noise fed into it, but this is pretty stupid.
I'm not overly fussy, but I would never actually build this as it's unplayable with this noise level.
I'm finding JFETs a little troublesome

Does anybody else seem to have these noise issues with JFETs?
Could it all change if I just built it and housed it in a metal box?

*sigh*

Thanks for any help,
Alex

[R.G.]

I can't tell from your description whether you're getting hum or hiss - only noise, which is accurate but not very helpful.

If you have 60 cycle hum, you have a grounding problem.

If you have 120 cycle hum, you have a power supply rectification/filtering problem

If you have hiss, you have a resistor-type or circuit design problem, or both.

[george]

have you checked that the connections on your input and output jacks are correct?

I built a jfet pedal once, it hummed like crazy until I realised that I had the input and ground wired the wrong way around on the input jack.  Once I swapped the connections around, the hum was much less.

hth ...

[Isaiah]

I think it's just picking up noise from my guitar and the mixer...

What I don't really understand though, is that when I roll down the guitar volume knob past, say, 8 or 9,
I get a really loud humming (60/120Hz) and with the guitar volume at minimum there's just hum.
The hum is about the same volume as the guitar when it's volume control is on full.

H(u)mmm.....

[Isaiah]

Woops...

Turns out the volume control issue is only with my guitar (it's a POS, but I love it).
My bass seems to be wired correctly and at zero volume the circuit just hums a little, however I think
this is noise picked up from the mixer PSU.

[foxfire]

so how would you compare it to the real deal?