Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Rubrburnr on September 05, 2015, 07:52:53 pm
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For those who can't read a schematic to save their life, is there a layout diagram for the Hoffman 5E3 amp? This is my first amp build and I may have found myself in over my head with this. This chassis is not going to be your standard chassis so things will be moved around a little... I searched on the forum and there might have been one a while back but it is no longer available. Thanks in advance!
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Follow the link at the bottom of this page to the Tube Amp Library of information.
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Not to discourage you from being creative, but the way components and wires are laid out in an amp is not trivial. It's part art, part science and part experience. I strongly encourage you to use a "known good" layout for your first amp build.
I improvised on my first build. It was a Tweed Princeton (mostly 5F2-A). I've re-built it twice since then. Learned a lot the hard way. Three other builds have been Blackface Fenders. The second and third were each progressively better and I started with the Hoffman layout for both circuits (2 Princeton Reverbs and a Super Reverb).
Good luck,
Chip
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Thank you Sluckey! I saw those and have looked at them however all the layouts I am seeing are not showing the output driver (at least that I am not seeing it). This is what brings up the trivial part for me Fresh_Start. I'm not getting too creative, just moving a couple things around. I should be able to follow it pretty easily. Hopefully...
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I saw those and have looked at them however all the layouts I am seeing are not showing the output driver (at least that I am not seeing it).
Output driver? Do you mean output transformer (OT)? It's shown on page 2. Page 1 shows how the tubes connect to the output transformer (OT). Look at this pdf and study page 1 and page 2. You will see the connection. If not, let us know.
http://el34world.com/Hoffman/files/Hoffman_5E3.pdf (http://el34world.com/Hoffman/files/Hoffman_5E3.pdf)
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I saw those and have looked at them however all the layouts I am seeing are not showing the output driver (at least that I am not seeing it).
Output driver? Do you mean output transformer (OT)? It's shown on page 2. Page 1 shows how the tubes connect to the output transformer (OT). Look at this pdf and study page 1 and page 2. You will see the connection. If not, let us know.
http://el34world.com/Hoffman/files/Hoffman_5E3.pdf (http://el34world.com/Hoffman/files/Hoffman_5E3.pdf)
Yes, the output transformer. I saw something on page 2 but it is beyond me to be able to read it. However, after taking a second look at it, it is starting to make sense!
What tube is showing on page 2? 5Y3GT?
Regarding the turret board, the dotted lines means the wire is on the flip side and soldered in?
What gauge of wire should be used for lacing up the turret board?
Page2, after the wire goes to the lamp, it goes to the Heaters. What / where are those?
Believe it or not, it is starting to click!!! Thanks again!!
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Here's another pdf you need to study...
http://el34world.com/Hoffman/files/CommonHookups.pdf (http://el34world.com/Hoffman/files/CommonHookups.pdf)
What tube is showing on page 2? 5Y3GT?
Correct.
the dotted lines means the wire is on the flip side and soldered in?
Correct.
What gauge of wire should be used for lacing up the turret board?
I like 22 AWG.
Page2, after the wire goes to the lamp, it goes to the Heaters. What / where are those?
The heaters are inside the tube. Look at page 1. You'll notice some of the tube socket pins are colored green. This is where you connect the wires from the lamp.
Believe it or not, it is starting to click!!!
After studying Hoffman's drawing and asking questions it will make more sense. It's even logical! :icon_biggrin:
Here's a pic that ties page 1 and 2 together as far as the tubes and OT are concerned...
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Excellent! That is exactly what I was picturing. After looking at the OT section, I don't see where to remaining wires get connected to. The yellow, green and orange wires... Also, I see a V1-2, V1-7 and a V2-2, what are those?
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After looking at the OT section, I don't see where to remaining wires get connected to. The yellow, green and orange wires...
Be specific. Which OT? Provide a link so I don't have to search for it.
Also, I see a V1-2, V1-7 and a V2-2, what are those?
Those refer to tube socket pins.
Hoffman's amps are not really a kit. Hoffman provides enough information to build these amps but a certain amount of electronics knowledge and other skills is required. You really may be in over your head. I think you would do better with a kit that provides detailed step by step instructions with illustrations.
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IMHO, and as someone that still has tons to learn, I think learning to read a schematic is almost a must before attempting a build, unless it is a true kit. And even then, a schematic is invaluable in trouble shooting. Just 2 more cents from someone anxious to see you succeed!
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After looking at the OT section, I don't see where to remaining wires get connected to. The yellow, green and orange wires...
Be specific. Which OT? Provide a link so I don't have to search for it.
Also, I see a V1-2, V1-7 and a V2-2, what are those?
Those refer to tube socket pins.
Hoffman's amps are not really a kit. Hoffman provides enough information to build these amps but a certain amount of electronics knowledge and other skills is required. You really may be in over your head. I think you would do better with a kit that provides detailed step by step instructions with illustrations.
I was looking at the actual OT for the speaker in hand and then comparing it to page 2 of layout. http://el34world.com/Hoffman/files/Hoffman_5E3.pdf (http://el34world.com/Hoffman/files/Hoffman_5E3.pdf)
ah ha... I see the connection now for the pins now!
Understandable that I AM in over my head (for sure) but I have to start somewhere. What I have found is the more difficult the learning curve is the better I will understand something (and by putting my hands on it). What you and everybody has pointed out by answering my novice questions, I am already 10x more knowledgable from when I started. I am overwhelming relentless on this project with a little optimistic thrown in there too...
IMHO, and as someone that still has tons to learn, I think learning to read a schematic is almost a must before attempting a build, unless it is a true kit. And even then, a schematic is invaluable in trouble shooting. Just 2 more cents from someone anxious to see you succeed!
I couldn't agree with you more! That was going to be secondary as I go along with this build. Look at it on the layout then move over to the schematic and realize the connection. Before I'd look at the schematic and move it to the side. It is becoming easier already finding things and correlating to the layout.
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Here's a very good site which can help you understand what the various components do in the circuit:
http://www.valvewizard.co.uk/ (http://www.valvewizard.co.uk/)
Links to essays on the left side. This will help you understand schematics, especially since there are many different ways to draw any given circuit. You learn to look for "grid return", "plate" and "cathode" resistors. "Filter", "coupling" and "tone stack" capacitors.
There is a TON of information in Doug Hoffman's Library. You do have to dig around for a while to find some of the most useful nuggets.
And I'll humbly suggest the "Useful References" sticky thread with the caveat that I need to go through and weed out dead links, etc. The tutorials on soldering alone should be very helpful.
Have fun!
Chip
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Take your time and look at all the links on the library page under my 5E3 section
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Here's a very good site which can help you understand what the various components do in the circuit:
http://www.valvewizard.co.uk/ (http://www.valvewizard.co.uk/)
Links to essays on the left side. This will help you understand schematics, especially since there are many different ways to draw any given circuit. You learn to look for "grid return", "plate" and "cathode" resistors. "Filter", "coupling" and "tone stack" capacitors.
There is a TON of information in Doug Hoffman's Library. You do have to dig around for a while to find some of the most useful nuggets.
And I'll humbly suggest the "Useful References" sticky thread with the caveat that I need to go through and weed out dead links, etc. The tutorials on soldering alone should be very helpful.
Thank you Fresh_Start! I'll be looking at those before I really get into the wiring of everything.
Take your time and look at all the links on the library page under my 5E3 section
That is exactly my plan. I've printed everything out and have looked at it daily, picked up a few more things here and there. Everything is starting to come into focus! I'm still drilling the holes into the chassis and will hopefully be ready for the wiring this coming weekend. Thanks EL34!