self made 100w amp>> working

**black_labb** · 18th December 2008, 03:44 PM

thought i'd make a dedicated thread for the amp. this is a bit of a continuation from progress thread

yesterday i tested it and found that it didnt work, but noise from test probes was amplified after the first gain stage. i suspected that it may have just been a dodgy tube, as the had come from a guy who gave me some for free, and i believe they were pulled from old tv's. i was right, was only a problem with the tube!!! i tried another and it worked well.

i got the thing running with 2 6550's in it (prob about 60w output), and had it on the coldest bias setting (which is supposed to make the amp sound quite sterile). i thought it was still not working, as i was listening for some hum, which never came. i thought i might as well try putting my finger on the lead just in case there was virtually no hum in the amp, and the buzz came!!! not only did i get the only amp i've designed myself as completely as possible working, but it has virtually no hum!!!

i was playing through a bass cab, but it still sounded great with the walnut guitar. i will rewire my 4x12 so it has the right impedance for the amp, and bias the amp with some 6l6's in it. once that is done i'll play around with the controls to see how i like the tone stack, and see if the mid shift control is as useful as i've hoped.

tubes should be cool enough to take out now. more details later

**DarwinStrings** · 18th December 2008, 08:26 PM

Congratulations Mr Labb. Well done on the no Hum. Next will be the box to put it in. Must be time to crank it up and give us a blast.

Jim

**Mr K** · 18th December 2008, 11:16 PM

This is something I know nothing about and congratulate you on your efforts , well done Black Labb

**old_picker** · 18th December 2008, 11:55 PM

well done man
its not easy makin an amp that doesnt hum

**black_labb** · 19th December 2008, 01:33 AM

just put the 6550's back in, and rewired the 4x12. because the 4x12 is quite insensitive (my 2x10 is significantly louder than it) i was able to push the amp into overdrive without getting too loud (according to me, the neighbours may think otherwise). the sound was great. the tonestack seems to be quite effective, and the switch to bypass it is nice as well. i was able to get some nice feedback from the strings, and the cabs mellow sounding alnico speakers helped ensure that it wasnt too harsh. sounds really good with guitar.
the sound with bass was also very nice. deep with plenty of definition. the equalisation is very useful.

i'm not sure wether i should buy 6l6's, or el34's.for it. thinking maybe el34's as they tend to be a tad cheaper, and the cheap brands get pretty good reviews.

thanks guys. the hum was a pleasant surprise. i did a couple things that helped the hum. i shielded the input cable by sticking it to the chassis with some copper tape (guitar shielding tape, i bought 50m of it a while back). i elevated the heaters 60v above ground (was so the preamp tubes wouldnt die quickly). using a choke helps alot and having quite a simple preamp helped as well.

sorry if im talking alot of technical jargon.

**Strungout** · 19th December 2008, 06:10 AM

Hey Black Lab,

That all makes my Champ Kit look very easy! It looks like you are right into this . Good on you and Well done.

Cheers

Greg

**old_picker** · 19th December 2008, 08:31 AM

Originally Posted by Strungout

Hey Black Lab,

That all makes my Champ Kit look very easy! It looks like you are right into this . Good on you and Well done.

Cheers

Greg

which kit did you buy??

**crazyhorse** · 19th December 2008, 11:07 AM

Nice one black_lab, must feel well proud....

**black_labb** · 19th December 2008, 11:42 AM

thanks guys. i am very proud, and i guess am am getting right into this

to answer oldpickers question to strungout, he got a champ kit from evatco.

**black_labb** · 19th December 2008, 02:00 PM

heres the inside. a bit ratty with some wires crossing the whole amp, but their not signal wires atleast.

heres the gear i tested it with. both instruments i made myself as well as the 1x15 cab which i need to make a grillcloth for.

heres the amp from the front

heres the amp from the rear

i plan on putting it into a shell. i'm thinking maybe a black vinyl one with timber front and rear. i can do some simple inlay for logo's and add some slits using the router for ventilation.

Thread: self made 100w amp>> working

Thread Tools

Search Thread

self made 100w amp>> working

Similar Threads

Am i working this out right ?

Some pens made from tired old flooring and another made of Cocobolo

working with one of u

What I've been working on

What are you all working on ?

Tags for this Thread

Posting Permissions