Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: acheld on May 09, 2021, 11:11:32 am
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While cleaning up some of my prior builds, I've had trouble with my grid stopper resistors to the first pre-amp tube -- they are just messy.
I've seen one or two of Sluckey's builds with an isolated post that will take the mechanical strain off of the tube socket pin and the resistor -- and this makes sense to me.
The question is: How are these isolation posts constructed? It seems simple, but the key is (of course) to know what components allow you to do this cleanly.
How are you folks accomplishing this?
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Here's what I use...
https://www.ebay.com/itm/303529423920?hash=item46abc37430:g:akQAAOSwu~RehM8x
They are also available with a male 4-40 stud But I prefer the females...
https://www.ebay.com/itm/254524164323?hash=item3b42d288e3:g:ahMAAOSwWs9dJL79
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https://hoffmanamps.com/MyStore/catalog/parts12.htm
3 lug terminal strip
(https://hoffmanamps.com/MyStore/catalog/images/IMG_2369.jpg)
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https://www.keyelco.com/category.cfm/Terminals/Threaded-Mount-Insulated-Terminals/id/941
p/n 11532 or 11531 depending on how thick chassis material is.
https://www.mouser.com/ProductDetail/Keystone-Electronics/11351?qs=%2Fha2pyFadugenAX7QbWVFM5gCgySXTKbSqFV4%2Fi9OGl6ahXE0JHrMA%3D%3D
https://www.mouser.com/ProductDetail/Keystone-Electronics/11352?qs=%2Fha2pyFadugenAX7QbWVFFVLi8QI8b9JjAIQSFhigvH5IgXJCj3Uhg%3D%3D
--pete
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More affordable!
https://www.ebay.com/itm/362043934117?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20200818141841%26meid%3Da147c496e550472994eb6a399e43fafd%26pid%3D101111%26rk%3D1%26rkt%3D12%26mehot%3Dpf%26sd%3D254524164323%26itm%3D362043934117%26pmt%3D1%26noa%3D1%26pg%3D2563228%26algv%3DDefaultOrganicWithAblationExplorer%26brand%3DConcord&_trksid=p2563228.c101111.m2109
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These all look perfect. Thanks!
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Wish I had a better layout shape for those turrets.
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Wish I had a better layout shape for those turrets.
Well yes, of course, but Visio is primarily a 2-D medium (and really good at that), and I think it would be tough to do much better.
You know, I've been realizing that building a great amp is not just about the circuit, but it's really about the large number of small things that add up to making that amp the best it can be.
This isolation post gets the grid stopper right to the pin, and alleviates stress on the pin and the shielded cable. By itself it does not make a great amp. But it is one of the -- many -- small things one does to make an amp shine.
LOL, apologies for getting philosophical about this topic. I've been studying for a music theory final exam . . . I'd much rather have been studying schematics. Say, there's an idea. :icon_biggrin:
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I've some of those insulated turrets recovered from old military equipments
but if I were to build something and I haven't it I'll use the solution from PRR
an alternative (on the cheap) will be to use hexagonal plastic spacers with a brass screw on the top (be careful when solder)
Franco
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https://hoffmanamps.com/MyStore/catalog/parts12.htm
3 lug terminal strip
(https://hoffmanamps.com/MyStore/catalog/images/IMG_2369.jpg)
I have hundred of these
PM your adress and I will send you some for free
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More affordable!
https://www.ebay.com/itm/362043934117?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20200818141841%26meid%3Da147c496e550472994eb6a399e43fafd%26pid%3D101111%26rk%3D1%26rkt%3D12%26mehot%3Dpf%26sd%3D254524164323%26itm%3D362043934117%26pmt%3D1%26noa%3D1%26pg%3D2563228%26algv%3DDefaultOrganicWithAblationExplorer%26brand%3DConcord&_trksid=p2563228.c101111.m2109 (https://www.ebay.com/itm/362043934117?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20200818141841%26meid%3Da147c496e550472994eb6a399e43fafd%26pid%3D101111%26rk%3D1%26rkt%3D12%26mehot%3Dpf%26sd%3D254524164323%26itm%3D362043934117%26pmt%3D1%26noa%3D1%26pg%3D2563228%26algv%3DDefaultOrganicWithAblationExplorer%26brand%3DConcord&_trksid=p2563228.c101111.m2109)
Very cool, and great price. Browsing that eBay seller's offerings I had to resist the urge to order a bunch of stuff that looks cool but I don't really need. Took me back to the days when I could go to Radar Electric on my lunch hour and browse around their surplus area.