I am shocked!

I am shocked!

Posted by jedrider (A) on July 21, 2012 at 16:31:58

Not shocked -- yet -- by electricity, but the Casablanca type of shocked that I just measured the resistances of the cathode bias resistors in a ten year old amplifier and they are all drastically different!!

So, I am going to replace all those out of spec with new 10 ohm resistors because I think measuring 30 ohms is way too much! I will note that the only resistor within spec is a newer one I had replaced. However, the other 'newer one' measures 13 ohms and appears distressed as it is in the circuit that keeps blowing up (as I have posted not long ago). I suspect the bias pot and I have thought about adding a fixed resistor to keep the bias under control -- can I even buy a replacement?

It's an Anthem One (EL34s). Any suggestions? Send it back for an upgrade (probably not in my budget, otherwise, I would have just bought another amp by now)?

I am electrically literate in some fashion and modding it myself is not out of the question. Diassembly is going to be a pain I can see. If I do make the effort, I wonder whether any bias circuit upgrades could be in the cards? Can I use lithium batteries? Build an autobias circuit?

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Topic - I am shocked! - jedrider 16:31:58 07/21/12 (24)

RE: I am shocked! - griboon 17:00:52 08/13/12 (0)

Follow-up! - jedrider 11:32:59 08/13/12 (0)

Solution in sight! - jedrider 22:40:28 07/21/12 (12)

RE: Solution in sight! - drlowmu 23:01:50 07/21/12 (11)

Not a Happy Ending - jedrider 16:27:15 07/22/12 (7)

Sorry to hear it - 1973shovel 17:11:22 07/22/12 (5)

I'm looking for a Variac now - jedrider 07:48:11 07/24/12 (4)

RE: I'm looking for a Variac now - drlowmu 19:17:26 07/24/12 (3)

Calm down - jedrider 07:09:12 07/25/12 (2)

RE: Calm down - Tre' 19:30:27 07/26/12 (0)

Calmed - drlowmu 16:05:20 07/25/12 (0)

Sorry, but the fat lady ain't yet sung...... - drlowmu 17:03:27 07/22/12 (0)

RE: Solution in sight! - Jim McShane 11:21:59 07/22/12 (2)

RE: Solution in sight! - drlowmu 12:36:21 07/22/12 (1)

RE: Solution in sight! - Jim McShane 13:35:59 07/22/12 (0)

RE: I am shocked! - drlowmu 18:05:55 07/21/12 (2)

RE: I am shocked! - jedrider 18:42:34 07/21/12 (1)

Lift a LEG !!!@!!!!@!!! - drlowmu 18:52:31 07/21/12 (0)

RE: I am shocked! - Chris O 17:12:17 07/21/12 (5)

RE: I am shocked! - Jim McShane 11:26:39 07/22/12 (4)

RE: "a 1 watt film resistor should do quite well" - 1973shovel 12:29:16 07/22/12 (3)

RE: "a 1 watt film resistor should do quite well" - TimFox 12:30:37 07/26/12 (0)

RE: "a 1 watt film resistor should do quite well" - Jim McShane 13:35:08 07/22/12 (1)

RE: "Put a scope probe on the cathode pin of the power tube " - 1973shovel 13:59:03 07/22/12 (0)

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