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Ceriatone / Overtone / Re: Ceriatone OTS Lunchbox 20 Speaker
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on: November 11, 2014, 12:28:42 PM
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I like 10" speakers with the OTS 20 with a closed back design and a slanted baffle that bounces the sound from the back of the speaker off the back side and out though a 'port' at the bottom. Something Ike this. You just have to add a damper board to the inside of the back to eliminate vibrations. This gives you clear, crisp lows and more headroom.
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Website, Store / Support / Re: Prinzetone hum problem
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on: September 02, 2014, 01:48:16 AM
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Tube voltages Pin 1. Pin 2. Pin 3. Pin 4. Pin 5. Pin 6. Pin 7. Pin 8. Pin 9 V1 12ax7 182 1.4 191 1.3 V2 12ax7 260 1.0 310 96 V3 6v6 .01 439 432 -42 0 V4 6v6 .01 435 433 -42 0 V5 5U4GB 310 312 I used a 5U4 rectifier tube to try to get closer to the original voltage (see http://www.classictone.net/40-18016.pdf). The layout calls for a GZ34. Not sure if that could be causing the hum, but thought I would include that info.
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Website, Store / Support / Prinzetone hum problem
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on: September 01, 2014, 02:51:37 AM
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I built a Prizetone kit with Larger Classic Tone transformers. The PT is a 40-18016 and the OT is a 40-18090. The amp has a hum. The hum is always there and increases when I roll back the guitar volume. The volume of the hum also increases as I change the volume knob of the amp. The hum increases with the tweed switch on (as you would expect). So far I have tried swapping tubes, different speaker cabs, different guitars, different outlets, all with the same result. I also noticed that the indicator bulb fluctuates in brightness just a bit but is not related to playing the amp. None of the other controls affect the hum and it does not change with the vibrato on or off. I have the bias set as low as it will go and increasing it adds more hum. Output tranny specs are here: http://www.classictone.net/40-18090.pdf. Power tranny specs are here: http://www.classictone.net/40-18016.pdf. Thanks in advance for any suggestions.
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Website, Store / Support / Re: 6v6 red plating on OTS 20 Lunchbox
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on: August 17, 2013, 02:27:38 PM
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Thanks Wyatt...
The problem wound up being that I had the polarity reversed on the 47uf / 450 volt cap nearest the first 12AX7 tube. That problem being resolved, now the amp is oscillating. Biasing does not resolve the oscillation. I am troubleshooting that now.
Also I have a question about the spare parts that were sent with the kit... There is a 1M resistor, a .22uf cap and a.1uf cap. Any ideas on what these parts are for? I'm still learning from the masters like you!
Grasshopper
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Website, Store / Support / 6v6 red plating on OTS 20 Lunchbox
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on: July 27, 2013, 01:07:11 AM
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I finished building my lunchbox 20w OTS and when I fired it up, the power tube closest to the mains fuse started glowing red when I flipped the standby switch to on. I swapped tubes with another set of 6v6s with the same result. I hear a low hum from the speaker cab when I flip the standby switch to on. As far as I can tel, the wiring looks good to both power tubes. Any suggestions?
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Ceriatone / Overtone / Re: OTS Lunchbox Kit
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on: July 25, 2013, 05:41:23 PM
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Hi sduck, I always save soldering the bus bar for last in case I need to change anything on the pots because I can move it a little to get behind it and work. I think it's just a habit but it probably makes more sense to solder as you go. The other spots were more than likely waiting on wires from the board or trannies.
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Ceriatone / Overtone / OTS Lunchbox Kit
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on: July 17, 2013, 07:18:49 PM
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I received my OTS Lunchbox kit and here's the first shot of the board in progress. This is my first time building on a PCB type kit, but it's a lot easier than hat I had expected. I added the big caps first so they make it easy to flip the board over and solder from the back.
I have more pics... The build is coming along and I now have the board completed, most of the off board wiring done, and am ready to wire up the board.
Got the trannies in today and will probably be ready for testing tomorrow night. I have more pics, but looks like 4 is the limit I can attach to this post. Will put together a slide show with a link when I finish the build.
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Website, Store / Support / Re: OTS 50 - Problems Upon Sound Test
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on: July 08, 2013, 12:57:45 AM
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ok, that elimiated the buzz/hum. Still no FET signal. Also, Switching the OD off seems to kill the signal. Basically, the amp always sounds as if it is in OD mode. PAB is apparently working. The output is very weak, not loud with Vol / Master on 10. The 'Level' and 'Ratio' controls for the OD section don't seem to have an effect.
-Chase
Hey Chase, I'm pretty much at the same level as you with a couple of other builds under my belt when I took on the OTS 50. I had a similar problem where the overdrive was 'on' always until I finally figured out that i was missing a wire from one of the relay coils (the little black rectangular box) in the foot switch circuit to the voltage divider (the three prong tiny black part) in your picture ending in #190851. Also, that voltage divider needs to be down flat (grounded by contact) to the chassis. I'm not sure if this has anything to do with the FET problem, but it couldn't hurt to check these two things... Anyway, good luck and it will be worth it when you get your bad boy straightened out. Your pics look like you did a really nice job! Cheers Sam
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