| Author |
 Topic  |
|
|
neonuke
Copper Member
Australia
32 Posts |
 Posted - 12/03/2008 : 05:14:00
|
I picked up a random lot of pedals, one of which is a Guyatone Funky Box.
I'm guessing it's not a very popular pedal, but hope someone can help me out.
With the effect off, the pedal is fine it bypasses through no problems, with the effect on and while not playing on the guitar, the pedal is NOISY and humming is LOUD, unbearably so.
Yet, as soon as I start strumming and the volume from my guitar reaches a certain level, the effected sound comes through with no noise, and when I stop strumming, it just outputs a constant LOUD low frequency hum again.
At first I thought it was the power adaptor causing the hum, swapped to another one but didn't make a difference. Tried all my guitars too and the same problem occurs. Is there some sort of interference that I need to shield, if so how? Is there something wrong with the grounding on the pedal?
Any help is most appreciated. |
Edited by - neonuke on 12/10/2008 03:51:01 |
|
|
Dr. Bob
Moderator
Australia
6593 Posts |
|
|
neonuke
Copper Member
Australia
32 Posts |
Posted - 12/08/2008 : 22:29:04
|
Dr Bob,
The pedal is the one pictured, the FB-X, not the tremolo model. They had a whole range of tube pedals, I believe the FB-X is no longer in production.
But anyway, still no luck getting rid of the humming, any ideas? |
 |
|
|
ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 12/09/2008 : 03:03:20
|
any chance of internal pics? schems?
Its usual for overdrives and distortions with high gain to have a bit of hum to them.
Or could be dried up capacitors...in that case, replace the caps with new ones |
Edited by - ChristoMephisto on 12/09/2008 03:04:57 |
|
|
|
neonuke
Copper Member
Australia
32 Posts |
Posted - 12/10/2008 : 03:48:44
|
quote:
Originally posted by ChristoMephisto
any chance of internal pics? schems?
I'll get them up soon
quote:
Originally posted by ChristoMephisto
Its usual for overdrives and distortions with high gain to have a bit of hum to them.
The hum in this is unbearably loud, it is MUCH louder than the effected signal when the guitar is being strummed.
|
|
|
|
Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 12/10/2008 : 08:20:17
|
Hi neonuke
What power supply are you using with it.
Hum is usually associated with poor filtering.
Maybe the Caps have gone a little south.
Give us as much info as you can.
Including, if you have the original power adapter.
A lot of tube based pedals actually run of approx. 12V AC not DC
The AC, is then rectified & filtered via a Voltage Tripler or Quadrupler.
To get the High voltage for the Plates on the tube.
Or in the case of the EHX pedals, they run the 12VAC into a 12V to 280VAC stepup transformer.
This transformer doesn't have to be very large, as the plates only need about 2mA (milliamps) each, on a typical 12AX7 or similar series.
In my Tube based pedals, I use the 12VAC to DC Quadrupler method, to get my plate voltages, if I'm trying to keep the pedal in a small case.
Regards Dr. Bob |
|
|
|
ssanyee
Silver Member
Hungary
288 Posts |
Posted - 12/10/2008 : 21:17:14
|
Hi,
I also have a Guyatone tube pedal, see internals here:
http://www.bossarea.com/forum/topic.asp?TOPIC_ID=4147&whichpage=9
This pedal has a specially designed DC-adaptor (I also use it for my BOSS pedals generally: really reliable and it can provide 0.2 ampers on 9.6 volts but to compare with BOSS PSA adaptor it has really less hum).
The problem with the hum is the heating of the tube: it needs min 0.15 ampers if the two heater setted serially in the pedal. In my Metal Monster the heatings are conducted serially in ECC83 and heated by this 9.6 volts. Without regulator IC the hum can be extremely high and the relatively high hetaer-current can cause it.
Using this adaptor I never can hear any hum in the output even at the highest gain adjustment.
The official Guyatone homepage about 'Flip' family:
http://guyatone.com/Flip.php
cheers |
|
|
|
neonuke
Copper Member
Australia
32 Posts |
Posted - 12/11/2008 : 09:23:20
|
the adapter I'm using is a generic adapter, one of those that can be adjusted to different voltages. It's set at 12V DC, (which is what the pedal asks for) and is capable of outputting 300mA
some internal pics:
can take more and post them, thanks! |
|
|
|
Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 12/11/2008 : 11:22:42
|
Hi neonuke
Thanks for the pics.
I'll put my money on the adapter,
you said it was a Generic type.
It's probably NOT regulated.
If you read Ssanyee's reply, it uses a regulated power supply adapter.
Regards Dr. Bob
|
|
|
|
neonuke
Copper Member
Australia
32 Posts |
Posted - 12/12/2008 : 08:51:11
|
cool, so where can I get a regulated adaptor from? do guyatone still sell their power adaptors i wonder? thanks everyone for your help, I'll try to track down the adaptor  |
|
|
|
ssanyee
Silver Member
Hungary
288 Posts |
Posted - 12/12/2008 : 10:23:11
|
Hi neonuke,
Here is a photo about my Guyatone adaptor:
At first you can try any well filtered/stabilized AC adaptor, like BOSS PSA-adaptor, hope it also brings positive result.
Keep us informed about any progress!
cheers |
|
|
| |
Topic |
|
Guyatone FLIP Funky Box FB-X
