Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: DuaneOh on June 24, 2022, 06:41:10 pm

Title: Vibrato sound on a non-vibrato amp?
Post by: DuaneOh on June 24, 2022, 06:41:10 pm

I have a '59 Fender Harvard 5F10 that is mostly original and am getting a faint fast vibrato, mostly noticeable when playing higher single notes, especially on humbucker equipped guitars. I haven't opened it up yet to look inside, I was hoping to get some direction before I go in. Any suggestions on where to look?  Thanks.

Title: Re: Vibrato sound on a non-vibrato amp?
Post by: sluckey on June 24, 2022, 06:58:27 pm

Got a fan in the room?

Title: Re: Vibrato sound on a non-vibrato amp?
Post by: DuaneOh on June 24, 2022, 07:21:57 pm

Quote from: sluckey on June 24, 2022, 06:58:27 pm

Got a fan in the room?

You are a genius! Turned off the fan and the vibrato went away. Thanks!

Title: Re: Vibrato sound on a non-vibrato amp?
Post by: brewdude on June 25, 2022, 01:15:24 am

That is soooo funny!


I was once pulling my hair out trying to find an oscillation.  It took two days to figure out it was the ceiling fan above the table I was working on. 

Title: Re: Vibrato sound on a non-vibrato amp?
Post by: zircontweezer on June 25, 2022, 04:51:51 am

So just to clarify it's a mechanical/audio effect of the fan blades rotating that makes the vibrato and not electrical interference? Just asking as I've never heard of that problem before but it is summer in the northern hemisphere so I guess the fans are back in use.

 

Title: Re: Vibrato sound on a non-vibrato amp?
Post by: shooter on June 25, 2022, 06:40:46 am

yes mechanical, mine sounds like a chevy 350 outside idling, been to the window 12 times no Chevy!  :icon_biggrin:

Title: Re: Vibrato sound on a non-vibrato amp?
Post by: PRR on June 25, 2022, 02:12:15 pm

Big blades are acoustic reflectors. Sometimes they reflect to your ear, sometimes away from your ear. Ceiling fan speed is right in the tremolo register.

Title: Re: Vibrato sound on a non-vibrato amp?
Post by: kagliostro on June 26, 2022, 10:28:12 am

And we spent time and $ to modify our amp's if they didn't have the feature  :l2: :l2: :l2:


Franco

Title: Re: Vibrato sound on a non-vibrato amp?
Post by: Greg on June 26, 2022, 11:21:48 am

Luckily, this amp didn't have a built-in tremolo circuit. It is not hard to imagine somebody like myself butchering an amp only to discover the fan problem after a 3-pages-long troubleshooting thread.

Title: Re: Vibrato sound on a non-vibrato amp?
Post by: brewdude on June 26, 2022, 05:20:20 pm

The other frustratingly simple noise rabbit hole I was almost sucked into…


A rattling sound that turned out to be a bowl of loose change.

Title: Re: Vibrato sound on a non-vibrato amp?
Post by: mresistor on June 26, 2022, 05:34:45 pm

Quote from: brewdude on June 26, 2022, 05:20:20 pm

The other frustratingly simple noise rabbit hole I was almost sucked into…
A rattling sound that turned out to be a bowl of loose change.

I went through similar situation,, strange metallic rattling, spent a good amount of time trying to find something wrong with the amp, then the cab only to find it was pots and pans vibrating in the pantry..

Title: Re: Vibrato sound on a non-vibrato amp?
Post by: brewdude on June 26, 2022, 06:51:11 pm

Snare drum?

Title: Re: Vibrato sound on a non-vibrato amp?
Post by: Lectroid on June 28, 2022, 09:19:20 am

Another:  I spent hours tracing down why my scope showed such dirty spikes and trash on a freak generator signal.  Then I discovered it was the power supply for the LEDs around my magnifying lens...