Problem maybe??

angry_young_poet · Post by **angry_young_poet** » Fri Jul 09, 2004 11:09 am

Should i be worried if my amp seems to make a humming noise even though the volume is at 0.. and if i try to put it between 0 and 1, the sound is kinda distorted, even though that's the clean channel.. past 1, it sounds great though..

otherwise, it sounds awesome, it's a great buy, well worth the money, and i got a crowther hotcake in a package deal with the amp..

So it was a good GAS day yesteray

B45-12 · Post by **B45-12** » Fri Jul 09, 2004 11:20 am

If it's a mains valve amp you should get avery slight hum at worst even at zero vol. If it irritates or intrudes then the first thought (for me) is the power supply electrolytic caps have dried out and may need replacing. Not generally a difficult or expensive option - half an houtr of tech's time to replace them.

The simplest option (since it's not allways too easy to test for stuffed mains caps) is to have them replaced first plus get the tech to check for other problems - put it in writing to contact you before doing other work.

philipnz · Post by **philipnz** » Fri Jul 09, 2004 11:31 am

Whats the amp?

angry_young_poet · Post by **angry_young_poet** » Fri Jul 09, 2004 12:09 pm

a vox cambridge reverb twin..

i just read what Polar Bear wrote about his auction for his C 30 and the mods he did...
http://www.trademe.co.nz/Music-instrume ... 131776.htm

and the harmony central reviews so maybe doing the mods is a good idea..

your thoughts?

philipnz · Post by **philipnz** » Fri Jul 09, 2004 12:18 pm

Go to http://www.voxtalks.com and do a search on the Cambridge mods. A good idea yes.

Polar Bear · Post by **Polar Bear** » Mon Jul 12, 2004 10:03 pm

you're fucked without the modification, however it's cheap to take th optocoupler out and install a 1mohm resistor in it's place (20c) however you'll need to replace the power chip to the 56watt job if you want to use it in a band situation.

Polar Bear · Post by **Polar Bear** » Mon Jul 12, 2004 10:09 pm

http://www.rsnewzealand.com/cgi-bin/bv/ ... kSubmit=Go

The part number is LM3875T or LM3876T. I had the LM3876T in mine. That's the 56 watt chip.

angry_young_poet · Post by **angry_young_poet** » Mon Jul 12, 2004 11:11 pm

surely you will lead me to your past contacts??

how much should i look at spending here?

let me know so i can rob that dairy in the corner!

Polar Bear · Post by **Polar Bear** » Tue Jul 13, 2004 11:23 am

If that link doesn't work then go to http://www.rsnewzealand.com and type in the part number. LM3876T. Then you go down click the order button and $25 later you've got twice the power. The distorting problem is a lot harder to fix within NZ if you want to keep the Tremolo. However if you don't care about the tremolo channel then it's 20c for a resistor. I've got all the diagrams and instructions on my computer still so we can sort something out!!

angry_young_poet · Post by **angry_young_poet** » Tue Jul 13, 2004 12:05 pm

great!!

I trust thee golden haired one to make my amp roar!!