I'm the first Polkie to fix an Ipod Tube Amp

ben62670

Well not really, but I think I am the first to blow one up:D:o

disneyjoe7

Somehow I didn't find that too surprising coming from you DOC.

ben62670

I was just running some sine waves, and all of a sudden no output. At first I thought it was my sound card. I was building an active XO with a Burr Brown OPA134. Everything was fine. I was running at 90db (annoying in the higher frequencies), and instantly nothing! The wiring is just as clean as the out side. There is 142vac (72x2) which kinda surprised me. Also 35vdc on the LM type (11 pin) chip amp, and a dinky little transformer.

disneyjoe7

Well the 35vdc seems odd to me doc. The 142vac didn't surprise me as much where did you read this?

ben62670

disneyjoe7 wrote: »

Well the 35vdc seems odd to me doc. The 142vac didn't surprise me as much where did you read this?

The 35vdc is normal for GC type amp, but the 72vac per tube kinda surprise me. Each tube has its own secondary.

disneyjoe7

Ben, can you place a signal on the input then scope it out where you lose it. But my thinking its the GC amp chip. I don't know just a 200 mile hunch.

ben62670

Apparently the tubes are "dual channel" like other sixes are. I swap tubes, and I have sweet tunes again.

SCompRacer

Are ya gonna crank it up again, until it hertz?:D

ben62670

I always screw up which amendment to plead. I usually quote the one "The right to keep, and arm bears":D

disneyjoe7

Ok old school tubes in the mix check Tube first.


Glad you got working again, seem like an easy fix. This time.

ben62670

disneyjoe7 wrote: »

Ok old school tubes in the mix check Tube first.


Glad you got working again, seem like an easy fix. This time.

I already have some cheap replacements on the way. FredV hooked me up with a site to get them cheap;)
http://www.thetubecenter.com/index.html
I am building a homebrew low voltage tube pre.