christmas present sonaro

[wolffman]

good morning. I own an old Sunn Sonaro. looking to get it fixed up for a Christmas present.

I bought this amp used about 10 years ago and played it about for about 4 years until it died ( i think the tubes crapped out) so i bought a new rig (it was time anyway). Recently ive thought it will do great as a practice amp/small gig amp- i know it isn't very loud but still has a nice warm sound and its nice and simple. my room is small and so are some of the venues i jam at so i think its suitable.

Not quite sure of the year, but its probably from the 70's. To replace the tubes to original type what brands should i buy?
will i still need to get the amp biased if i replace with original brand of tubes?
Is there another brand of tube that replicates the original? or improves sound quality without needing additional work?

Thanks a bunch.

[djc]

sounds like it needs a good going through.  replacing tubes, even same brand would require rebiasing.  more likely what needs done is the capacitors.  and if it crapped out, possibly a transformer.  take it to a reputable store with a tech who knows and understands tube amps.  these things can be resurrected from the dead(mine was) for a couple hundred(well worth it) and will probably become your main playing amp again.  put a 215 cab under it and it's plenty loud and creamy tone.

[Sledgeguitar]

please keep me posted as to what you do to it. i am thinking about taking mine to a local Fender tech for an overhaul....i would like to know what i am getting into.

[wolffman]

if all it needs are tubes, than could i bias it myself?

how hard is it to DIY?

is there a manual i can read?

[djc]

do a search on amp bias, it has been discussed in depth on this site.  basically a few voltage measuremnts, a lot of math and twisting a pot.  not difficult but there are voltages in a tube amp when off and unplugged that are capable of killing you.  know what to do before even opening it.

no I don't do my own.  I have a great tech I take it to.