New Build: Ceriatone Replica OTS 50W

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dwietzel
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Re: New Build: Ceriatone Replica OTS 50W

Post by dwietzel »

martin manning wrote: Sat Jul 08, 2017 2:19 pm The DC is very well filtered by that point so there is really no worry.
Thanks Martin! Just double checking. Would rather catch it now rather than try and figure out later :-)
dwietzel
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Re: New Build: Ceriatone Replica OTS 50W

Post by dwietzel »

Relays, FET and v1 stage wired up.

Similar coax question for J1 and J2. Would it be OK for these to ride on top of the wires for the next 2 stages?

I did not make these long enough to run neatly up the back and over to the preamp board.

Thanks
Dave
Stage 1 Relays FET.jpg
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martin manning
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Re: New Build: Ceriatone Replica OTS 50W

Post by martin manning »

Where's your OD trim pot located? If it's on the back by the speaker jacks, I'd take the coax straight back and then turn right, running behind the tube sockets.
dwietzel
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Re: New Build: Ceriatone Replica OTS 50W

Post by dwietzel »

Preamp is done - will double check later.

Just taking a minute to thank everyone who has helped me get this far. I could not have done it without the support of this forum.

Dave
Preamp Done.jpg
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dwietzel
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Re: New Build: Ceriatone Replica OTS 50W

Post by dwietzel »

OK finishing up the Power Cap board.

I have seen people run the wire from the standby switch to the Cap board underneath or across the wires of the Power tube section.
Since this area includes the wires coming from the Phase Inverter, wouldn't it be a problem running a 120 AC wire across it?
Any advice and information would be appreciated. Thanks!

Dave
Standby To Caps.jpg
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dwietzel
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Re: New Build: Ceriatone Replica OTS 50W

Post by dwietzel »

dwietzel wrote: Sun Jul 09, 2017 3:06 pm OK finishing up the Power Cap board.

I have seen people run the wire from the standby switch to the Cap board underneath or across the wires of the Power tube section.
Since this area includes the wires coming from the Phase Inverter, wouldn't it be a problem running a 120 AC wire across it?
Any advice and information would be appreciated. Thanks!

Dave
Standby To Caps.jpg
Well I answered I believe part of my question. It is actually the 345 volts off the PT through the rectifier board so if I am reading this right it would be 345 DC at Standby but it is still unfiltered at that point. Should it matter?
dwietzel
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Re: New Build: Ceriatone Replica OTS 50W

Post by dwietzel »

PT Wiring. Would this be correct?

Black - IEC N connection
White - Power Switch

Orange - Star Ground

Red/Yel - BIAS Power
Red/Blue - Star Ground

Thanks
Dave
PT Wiring.jpg
PT Data Sheet
40-18004.pdf
Ceriatone Diagram
Ceriatone 100W v2.jpg
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martin manning
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Re: New Build: Ceriatone Replica OTS 50W

Post by martin manning »

Red/Yel is secondary CT (ground), Red/Blue is bias tap. White primary is line neutral, black primary goes to AC power switch. Line hot goes to fuse center lug, then connect fuse side lug to AC power switch.
dwietzel
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Re: New Build: Ceriatone Replica OTS 50W

Post by dwietzel »

martin manning wrote: Tue Jul 11, 2017 3:10 am Red/Yel is secondary CT (ground), Red/Blue is bias tap. White primary is line neutral, black primary goes to AC power switch. Line hot goes to fuse center lug, then connect fuse side lug to AC power switch.
Well nothing like being completely wrong. I could not tell from the PT Data Sheet. Am I missing something?
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martin manning
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Re: New Build: Ceriatone Replica OTS 50W

Post by martin manning »

All the info is there, and the wire colors are the usual standard. The black and white primary leads could go either way, but you might as well follow the US standard for hot and neutral.
dwietzel
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Re: New Build: Ceriatone Replica OTS 50W

Post by dwietzel »

martin manning wrote: Tue Jul 11, 2017 10:09 am Red/Yel is secondary CT (ground), Red/Blue is bias tap. White primary is line neutral, black primary goes to AC power switch. Line hot goes to fuse center lug, then connect fuse side lug to AC power switch.
Does this look right? For some reason your description of the fuse wiring seems opposite of what I am doing.
Thanks,
Dave
PT Wiring 3.jpg
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martin manning
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Re: New Build: Ceriatone Replica OTS 50W

Post by martin manning »

I would switch the wires on the fuse holder. With the hot lead connected to the side terminal it's possible to get shocked when replacing the fuse if the amp is connected to the mains. You should be able to power it up with no tubes installed and get some voltages now, eh? I recommend using a current limiter though.
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norburybrook
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Re: New Build: Ceriatone Replica OTS 50W

Post by norburybrook »

martin manning wrote: Wed Jul 12, 2017 1:43 am I would switch the wires on the fuse holder. With the hot lead connected to the side terminal it's possible to get shocked when replacing the fuse if the amp is connected to the mains. You should be able to power it up with no tubes installed and get some voltages now, eh? I recommend using a current limiter though.
wise words. This should be part of all amp build safe practices but you'll see lots of occasions where it's not wired this way. I've had a shock from an amp because of this.


Marcus
dwietzel
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Re: New Build: Ceriatone Replica OTS 50W

Post by dwietzel »

norburybrook wrote: Wed Jul 12, 2017 12:05 pm
martin manning wrote: Wed Jul 12, 2017 1:43 am I would switch the wires on the fuse holder. With the hot lead connected to the side terminal it's possible to get shocked when replacing the fuse if the amp is connected to the mains. You should be able to power it up with no tubes installed and get some voltages now, eh? I recommend using a current limiter though.
wise words. This should be part of all amp build safe practices but you'll see lots of occasions where it's not wired this way. I've had a shock from an amp because of this.


Marcus
OK - I will definitely get that done and then need to finish with the Heater wire installation and then be ready to hopefully start testing. Couple of more questions:

1. For the second fuse then should I wire the ground to side and the lead to tip (not sure if this is similar situation as Power fuse)?
Secondary Fuse.jpg
2. For the wire from Standby to the Power Caps, since that is unfiltered DC off of the rectifier, should I not place that wire up high away from audio coming from the phase inverter? I have seen others run this line down low on the chassis across other lines. Again could just be my lack of knowledge here.
Standby To Caps.jpg
Thanks,
Dave
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martin manning
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Re: New Build: Ceriatone Replica OTS 50W

Post by martin manning »

1. Yes, that will prevent a shock when inserting a fuse, in this case the amp would have to be plugged in with the mains switch turned on for that to occur. Fusing the center tap is a questionable practice since there will still be high voltage present if it opens (you should really fuse both red leads), and when the bias supply comes from a tap on the HV secondary as it does in your case, the bias supply caps will likely be destroyed when the fuse opens.

2. No problem. Run the standby switch wires down on the chassis, parallel to each other or twist them together, and arrange other wires to cross them at a right angle.
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