Firebass 700 trouble

[fenderbass85]

First off new to the forum here. Hopefully someone can give me some insight to me troubles here. i have a firebass 700 that ive owned for 7 years with trouble free performance, been giged over and over. i play it through a peavey 1516 4 ohm cab. just recently at practice it starting dong what i would call clipping. the green light on the front goes dark and sound cuts out momentarily and comes right back on. Seems to only do it when hitting lower notes. I dont tend to play that hard and i'm sitting at 5 on my pre gain and 4-5 on my master. checked connections, tried different cords, different basses, and i have another 1516 4ohm cab that i tried does it on everything. so i know its the amp. i turned the preamp down very low 1-2 and turned the master up to make up the difference and it seems to cut out less this way. I took the front of to get to all my knobs and cleaned very throughly with contact cleaner and can air. no difference. anyone had the same or similar trouble with it. I really love this amp due to its reliability, and the sound i get out of it combined with my cab after alot of tweeking over the years. thanks

[craig.p]

First thing I'd do would be to disconnect and reconnect about ten times every plug and pin and other connector inside the amp, just in case something's come unseated or gone oxidized from TN humidity.

If the amp has an effects loop, connect the in and out with a guitar cord, on the suspicion the return jack's NC circuit contacts have corroded. (Long shot but try it anyway.)

Try isolating the amp from all vibration by putting a pillow or similar underneath it. Don't block any air vents, though.

Run the amp standing up on its side and see if you get the same problem.

We are looking for non-electronic problems first.

[bassplayer1954]

My Firebass 700 does the same,but only at places,bars,ect that has shotty wireing.Other than that it runs like a champ.

[georgestrings]

Originally Posted by craig.p

First thing I'd do would be to disconnect and reconnect about ten times every plug and pin and other connector inside the amp, just in case something's come unseated or gone oxidized from TN humidity.

If the amp has an effects loop, connect the in and out with a guitar cord, on the suspicion the return jack's NC circuit contacts have corroded. (Long shot but try it anyway.)

Try isolating the amp from all vibration by putting a pillow or similar underneath it. Don't block any air vents, though.

Run the amp standing up on its side and see if you get the same problem.

We are looking for non-electronic problems first.

Yeah, I had a Mark VIII that acted up like that, it turned out to be a corroded ground connection between the boards inside...


- georgestrings

[fenderbass85]

Thanks guys. I'm at the firehouse today. I'm going to mess with it tommorrow. I'll keep yall informed.

[fenderbass85]

Thanks yall. I'm at the firehouse today so I'm gonna mess with it tommorrow. I'll keep yall informed.

[ezstep]

Dood... you broke a PEAVEY? You are my new hero!!!

[BassmanPaul]

If the amp is fan cooled check that the cooling flow is not impeded by dust and crud. If it is - vacuum the unit out using a soft paint brush to dislodge dirt from the heatsinks.

[fenderbass85]

yeah ezstep, i hope i didnt cause i really like my ole firebass amp. may be heavy but i get a really good tone/sound combined with my cab.

[fenderbass85]

Originally Posted by BassmanPaul

If the amp is fan cooled check that the cooling flow is not impeded by dust and crud. If it is - vacuum the unit out using a soft paint brush to dislodge dirt from the heatsinks.

yeah, i'm hopefully going to pull it completely apart tommorrow if i can find the time, and clean it and see if i can find anything.

[ezstep]

Originally Posted by fenderbass85

yeah ezstep, i hope i didnt cause i really like my ole firebass amp. may be heavy but i get a really good tone/sound combined with my cab.

I leave a Peavey Max700 and one BagEnd cab at the church all the time (we do several concerts per year - some "bluegrass" gospel and some complete orchestra (violins, flutes, cello, brass, etc.) with 16 member choir behind us. Yeah, the tones are pretty good, but I obviously cannot crank it.

[fenderbass85]

well i didnt have the time to fiddle with it this week so took it to a local music store that a friend works at in town its on the bench there right now hopefully will hear from them tommorrow. Borrowed a friends gk backline 600 and was very dissapointed with it. doesnt drive my 1516 cab like my firebass. I WANT MY AMP BACK!

[craig.p]

Yeah, those things are sort of DEAFENING.