Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: burnteric on April 10, 2021, 04:47:26 pm
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I'm in the process of planning and building my first amp. It's a kit amp so I think it will be a good starting point. I've been reading lots of very helpful information from all over the interwebs from planning to testing through tweaks and mods and beyond.
I've inventoried all my components, laid out my eyelet board (nothing soldered yet), and drawn up a chassis layout plan.
Regarding the chassis layout, I have some questions I was wondering if some of the more experienced builders can shed some light on.
1. How important is spacing regarding the components? Are the PT and OT supposed to be on opposite sides of the chassis for isolation or is it more a weight distribution thing? What are the proximity effects of having pre-amp and power amp tubes near emitters? I've seen amps where everything is crammed together and some where everything is spaced apart. What might be the reasons for each?
2. What are typical "best practices" regarding chassis layout? I'm sure there are many many factors but what advice would you give someone who might otherwise simply arrange them aesthetically?
I've attached an AutoCAD mockup of my components on the chassis. Feel free to comment, berate, or otherwise point me towards a new way of understanding this seemingly simple, yet deceptively complex concept.
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I'm in the process of planning and building my first amp. It's a kit amp so
Whose kit? Did they provide a schematic and layout?
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Maybe this will give you a starting place to think about this and plan
https://el34world.com/Forum/index.php?topic=17406.0
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I'm in the process of planning and building my first amp. It's a kit amp so
Whose kit? Did they provide a schematic and layout?
Its the Weber 6S100 build kit. I have both the schematic and layout for it, yes. I've tried to follow the layout but I'm using a chassis that I've provided myself and its larger. The layout for the 6S100 I've tried to follow but in prepping the drawing I starting wondering what issues might arise.
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Thank you tubenit I'll read this! I couldn't dig that up when searching around on the site. I appreciate it!
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Look at the Weber 6S100 chassis and copy that. Even better, just buy the Weber chassis. A word of caution about the 6S100... The bias circuit will allow you to adjust the bias voltage all the way to zero! Doing so will quickly kill the output tubes.
The 6S100 is based on the Sunn 100. All Sunns used this layout...
(http://sluckeyamps.com/sunn/sunn_05.jpg)
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Ok, so it took me a while to get this up and running because I wanted to take my time and get things right and learn as much as I could in the process (as well as working 60 hr weeks since March). It was my first amp build ever and it was the Weber 6S100 kit. I'm really proud of how it came out and wanted to say thanks to you all for your guidance and insight. It fired up beautifully on the first power up. I'm somewhat happy with the tone (volume is disastrous but I knew that going in). I didn't necessarily want or need a bass amp but I'm glad I tried with this so I wanted to see what I could do!
Lead dress is important to me since I work in Broadcast and AV wiring professionally and cable neatness has always been something I appreciated and valued as an installer. I wanted to take the time to make it clean and tidy.
For the grounding scheme, I used a multiple star system with each star being isolated with isolation washers which all bleed back to a single "main" star near the power stage which grounds to chassis.
For the heater wiring, I decided to go under the board and even used a terminal board to enable some flexibility if things didn't work out as planned. I probably won't use that terminal board next time but in this case, it worked great.
I did not stray from the schematic wiring wise but I did replace a number of components due to poor quality. I swapped out all my pots for Alphas and replaced the lamp. I also had a number of issues from the warehouse/inventory of what was shipped but they promptly got the parts I needed so all was well. Some parts were incorrect, others not even included in the original shipment, but in a way, it was all good because it forced me to look closely at what I was doing and be sure that I understood the process and not try and be a smart guy about cutting corners.
I appreciate any advice/comments/feedback on the build and I look forward to the next ones (smaller for sure).
Thank you!