Hiss is killing the tone using Arcturus by VeriTone

[Tomward]

O.K. I'm the newest guy onboard here.
Thank you very much for the approval.

My current problem which I have not been able to fix involves a pedal by a company called VeriTone.
The pedal is the "Arcturus"

Here is the company: https://www.veri-tone.com/pedals/arcturus/

Here is R.J. Ronquillo selling the pedal...and what an awesome performance he gives.
It was the first 3 minutes or so! Awesome.

Awesome right?

So I paid $225 for mine and the volume pot has a constant hiss/buzz that kills the quiet tones.
Turn the volume knob up and you get louder hiss.

It's unplayable.

I have a 1SPOT power supply just in from Sweetwater.No better.
I'm plugged into the same outlet.No better.
I tried to isolate the ground thinking I could route the his/buzz to ground.No can do.

So I cut my time / frustration losses and here I am.Hat in hand.

What can I tell you so that you can help me?
No schematic is available.

 

[veri-tone]

Let me just clarify a couple of things here. First, the entire enclosure is made of aluminium and when all signal and power cables are plugged into it, acts as a Faraday cage. So the length of the transistor wires matters very little.
Second, I use multi-turn trimmers because they give me more precision when biasing the transistor.
Third, while this circuit shares some similarities with the Hudson Broadcast, it was designed completely independently and uses different components (the only component that is the same is the transformer). They sound rather different, too.

Now, for a possible solution - if you have a multimeter, set it to measure voltage. Connect one pin to ground and one to the collector of Q2. Rotate the trimmer until the voltage reads around 4.5V. If you're still getting hiss, it could be a leaky cap or even a bum transistor (I build these with Raytheon transistors from 1966). I try my best to QC these before they leave the house, but hiss happens. You can get in touch with me through Instagram and send it back for a free repair, or even a refund if you'd like.

I should also add that out of 200+ pedals built this is maybe the 4th or 5th complaint I get about it being noisy.

 

[JTEX]

Here's my unsolicited second opinion. It's most likely a noisy transistor, if other units of the same design are not particularly noisy. Old germanium transistors can be all over the place.

As for long legs, they can still cause problems even in a shielded enclosure by adding parasitic coupling between stages. This is mostly a concern in really high gain circuits, where even the wire routing (if unshielded) and the PCB layout can make a very real difference and might cause oscillations/squealing. Not hiss, though. Hiss (white noise) comes from noisy active components, as well as suboptimal circuit design. Specifically, resistors in the signal path that are higher value than they should be will degrade the achievable noise floor. A single lowly 10k resistor in series with the signal from the pickups will add 3dB of noise right then and there, and I see such design choices a lot. It seems to me that very few designers actually do noise calculations or are even aware of the various contributors to overall noise. Just backing off the guitar's passive volume pot (250k or 500k) can easily double the hiss due to the additional resistance inserted between pickups and output jack. Higher source resistance = more hiss.

As a designer myself, I do think the better course of action would have been to contact the manufacturer for a possible solution before jumping to complaints on forums. Especially since it's a one-man operation, so it's not like you have to go through some overseas call center. Surely he should be the first one to ask for help.

 

[veri-tone]

Yeah, I'm thinking most likely either the bias went out of whack or the transistor just cried uncle. I try my best to test them before they go out the door but Germanium is highly susceptible to temperature variations. The transistors I've been using for the Arcturus for the past 2 years all come from a box of NOS Raytheon 2N404s that I bought locally. Other components in the circuit are also vintage, such as the carbon comp resistors and some of the capacitors.

 

[Giorfida]

Yeah, I'm thinking most likely either the bias went out of whack or the transistor just cried uncle. I try my best to test them before they go out the door but Germanium is highly susceptible to temperature variations. The transistors I've been using for the Arcturus for the past 2 years all come from a box of NOS Raytheon 2N404s that I bought locally. Other components in the circuit are also vintage, such as the carbon comp resistors and some of the capacitors.

Not saying it’s a smoking gun here, but in tube amps, older carbon comp resistors are the #1 suspect when it comes to “Rice Krispies syndrome” (snaps, crackles,pops and hiss).
Would definitely like to hear the result if he takes you up on the offer to repair!

 

[veri-tone]

Yeah but in tube amps they usually have 200+ volts running through them. I designed this circuit to take up to 18v. Using 1/4w resistors, that is like nothing to them. And yeah I measure them all for drift before they go on the board.

 

[veri-tone]

Just so the rest of the forum knows, I've refunded Tom for the defective pedal and he will send it back to me. When I diagnose it, I will post the results here.

 

[hamerfan]

Just so the rest of the forum knows, I've refunded Tom for the defective pedal and he will send it back to me. When I diagnose it, I will post the results here.

Good move!