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Post by stuey222 on Jul 7, 2008 14:02:25 GMT -7
Well, I just got the chance to finally plug it in and give it a go and no sound is coming out of the amp. I've got the speaker cable hooked to the 8 ohm jack connected to the Z Best (8 ohm), the power tubes look fine, so what could be the culprit here?
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Post by benttop (Steve) on Jul 7, 2008 14:09:51 GMT -7
No sound is usually one of three things: 1. Inadequate connection to the speakers; 2. A rectifier tube; 3. A disconnect between guitar and amp. Do you hear any hiss at all, with volume wide open? If so then suspect your guitar cord. If not, check your speaker cable again, and if that's ok, you may have a damaged rectifier tube.
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Post by stuey222 on Jul 7, 2008 14:12:49 GMT -7
No hiss, checked that first, tried different guitar cords, nothing. Rectifier didn't get warm, so it could be that, I just bought the speaker cable, but how would I test that?
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Post by benttop (Steve) on Jul 7, 2008 15:48:05 GMT -7
No hiss, checked that first, tried different guitar cords, nothing. Rectifier didn't get warm, so it could be that, I just bought the speaker cable, but how would I test that? You would need some way to check that everything is connected right and not shorted out. You can use a DMM for that, or a bug light. All a bug light is is a light bulb with a battery that you use to close the circuit through your cable. If that doesn't make sense, go buy one of these: www.zzounds.com/cat--2354But really, you should have a spare rectifier anyway. Go get one of those and if that doesn't solve your problem, you still have a spare, which is a good thing.
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Post by stuey222 on Jul 7, 2008 16:02:47 GMT -7
Thanks, Benttop, I'm pretty sure it's the rectifier, I hooked up my Blues Jr. to the Z Best with the speaker cable and it worked fine, so I'm definitely thinking rectifier. Aren't tube rectifiers supposed to get really hot anyway?
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Post by benttop (Steve) on Jul 7, 2008 16:12:50 GMT -7
Thanks, Benttop, I'm pretty sure it's the rectifier, I hooked up my Blues Jr. to the Z Best with the speaker cable and it worked fine, so I'm definitely thinking rectifier. Aren't tube rectifiers supposed to get really hot anyway? I never felt mine while it was hot, so I don't really know how hot they get, but I would think you wouldn't want to touch it!
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Post by kruzty on Jul 7, 2008 19:02:46 GMT -7
Here are a couple of "obvious" things to check:
- The Standby switch is in the right position - The fuses are OK (I don't think the jewel light would be on if that was the problem, but you might check them).
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Post by awesome on Jul 7, 2008 19:23:55 GMT -7
the rectifier should be pretty hot if its been running for 5-10 minutes. is it not glowing either?
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Post by stuey222 on Jul 7, 2008 19:45:39 GMT -7
Checked fuses and the standby switch, neither were wrong, the rectifier never heated up or started glowing, so I'm pretty sure that's it.
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Post by DRZ on Jul 8, 2008 4:49:05 GMT -7
Checked fuses and the standby switch, neither were wrong, the rectifier never heated up or started glowing, so I'm pretty sure that's it. That's a good bet Stuey. But I would change the Ht fuse along with the new 5AR4/GZ-34 Tube Rectifier. It might look OK but if the Rectifier failed 99% the Fuse went to. DR.Z
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Post by stuey222 on Jul 8, 2008 6:35:36 GMT -7
Is that the 1/2 amp or 3 amp fuse? Does voltage matter?
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Post by robbz on Jul 8, 2008 9:01:05 GMT -7
result?
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Post by DRZ on Jul 8, 2008 10:17:45 GMT -7
Is that the 1/2 amp or 3 amp fuse? Does voltage matter? If the indicator light lites up the just the 1/2 AMP MDL , HT fuse, that is Slo-Blo type 250V AC rating. Radio Shack is a good source. Z
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Post by stuey222 on Jul 11, 2008 8:31:13 GMT -7
So this might stump Doc now, but I put in the recto tube Eddie sent me, and the amp still doesn't work. No sound, but all the lights work. Still no heat to the recto tube. This is getting very frustrating...
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Post by benttop (Steve) on Jul 11, 2008 8:45:29 GMT -7
So this might stump Doc now, but I put in the recto tube Eddie sent me, and the amp still doesn't work. No sound, but all the lights work. Still no heat to the recto tube. This is getting very frustrating... Time for a tech if you ask me.
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Post by stuey222 on Jul 11, 2008 8:47:45 GMT -7
Probably back to the store, I'm not messing with throwing all that cash towards it when it was DOA. Either that or I'll see if the store will cover the costs to ship it to Doc.
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Post by stuey222 on Jul 11, 2008 14:00:32 GMT -7
Ok, so it's all works now, the 5AR4 was the culprit! I believe the EF-86 is microphonic, I've got some hiss and it gets louder when I hit the Overdose switch. I tapped it and I get some ping. It's the EF-86, right?
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Post by benttop (Steve) on Jul 11, 2008 14:06:29 GMT -7
That tube has a lot of gain going on with the OD on. I've never tapped mine but I'm imagining that you'll definitely hear something if you do.
This amp has a lot of gain if you twist the volume control all the way up. The amount of hiss vs the amount of sound coming from your guitar is going to be tiny.
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Post by stuey222 on Jul 11, 2008 15:14:21 GMT -7
Yeah, but there's quite a bit of hiss going on. Nothing major, but less than from what I've gathered by being here on the boards. Another thing, does your EF-86 have a rubber cover on it?
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Post by benttop (Steve) on Jul 11, 2008 16:12:47 GMT -7
Yeah, they all have either a shrink wrap cover or those rubber bands that are used to keep tubes quiet.
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Post by stuey222 on Jul 11, 2008 16:17:27 GMT -7
It's like a rubber glove that fits over the top. Then a holder is built into the amp.
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Post by benttop (Steve) on Jul 11, 2008 16:58:08 GMT -7
Yep. I have several like that.
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Post by myles on Jul 18, 2008 13:25:25 GMT -7
Thanks, Benttop, I'm pretty sure it's the rectifier, I hooked up my Blues Jr. to the Z Best with the speaker cable and it worked fine, so I'm definitely thinking rectifier. Aren't tube rectifiers supposed to get really hot anyway? Rectifier tubes get hotter than just about anything in the amp. If it is not hot it is dead. If it is dead, before it is replaced make sure your output tubes are good as a shorted one can take out your new rectifier.
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