New guy needing help

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geoff 1965
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Re: New guy needing help

Post by geoff 1965 »

I have successfully contacted heyboer myself,I would get onto amppartsdirect.com they sold you the transformer and should have supplied a schematic with specs with it.
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Resonance77
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Re: New guy needing help

Post by Resonance77 »

Sorry for the delay in response. I'm on the road for work right now and for the next couple weeks.

I finally got in contact with Heyboer. I received the schematics via email, so I now have the specs to work from.

The more I research and learn, the more I am leaning towards just building a 6v6 plexi and saving the parts I have aquired for the JCM800 preamp stage for a true 800 build. I don't think I will be able to accomplish what I want to accomplish with the 2204 pre on a 6v6 power section and have it sound like what I want it to sound like.

I haven't had much time to work on learning any of the schematic programs. I got a call to hit the road for work shortly after the post I made asking for program suggestions. I would like to learn the KiCad stuff and how to do these layouts and bom lists. It would make a scratch build much easier. I am currently trying to put this build together by hand (pencil and paper) in the limited few hours a week I am not working, on a **** old laptop in **** hotel rooms across multiple states.

So the plan right now is to make an 18 watt plexi running a 6v6 power section, ss rectifier, adjustable fixed bias, negative feedback and presence. I'll update once I get home and get a grip on this thing. I'm over my head more than I thought I would be.
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geoff 1965
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Re: New guy needing help

Post by geoff 1965 »

Can you post the specs heyboer sent you for the transformer?
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Resonance77
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Re: New guy needing help

Post by Resonance77 »

geoff 1965 wrote:
Sat 07/24/21 5:40 pm
Can you post the specs heyboer sent you for the transformer?
I will try. I have the files in an email. I just have to figure out how to get them from there to here. They are excel format.
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Resonance77
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Re: New guy needing help

Post by Resonance77 »

geoff 1965 wrote:
Sat 07/24/21 5:40 pm
Can you post the specs heyboer sent you for the transformer?
You do not have the required permissions to view the files attached to this post.
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geoff 1965
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Re: New guy needing help

Post by geoff 1965 »

Not relevant to you if you are diode rectifying but the 5V supply is only rated at 1.5amp,both the GZ34 and 5Y3 draw 2 amps so don’t know what they were thinking there?
Thanks for posting the specs and good luck with your build.
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Resonance77
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Re: New guy needing help

Post by Resonance77 »

geoff 1965 wrote:
Sat 07/24/21 6:50 pm
Not relevant to you if you are diode rectifying but the 5V supply is only rated at 1.5amp,both the GZ34 and 5Y3 draw 2 amps so don’t know what they were thinking there?
Thanks for posting the specs and good luck with your build.
EZ81, maybe?
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geoff 1965
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Re: New guy needing help

Post by geoff 1965 »

EZ81 uses the 6.3V tap which is plenty at 1.5amp,it might just be a “typo” with the 5V supply?
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Re: New guy needing help

Post by Bieworm »

EZ81 is just as good as having NO tube rectifier. Just go SS and call it a day. You can always add a 100R or 150R sag resistor after the rectifier diodes and have the same effect. I challenge you to hear any difference.
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Re: New guy needing help

Post by TriodeLuvr »

You must have had a bad experience with that tube. I've owned 50-year-old audio gear with the original 6CA4 still going strong.

As for sag resistors, that's not the only issue. Peak power supply voltage can be very high with a SS supply when first turned on. All the caps and other components need to be capable of handling that. 450V caps aren't expensive, but all the decoupling caps all the way down the line into the preamp will need that voltage rating if the PS is solid state.

Jack
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