Topic on tubes

Schematics, layouts & other technical mumbo jumbo.

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Doc Holliday
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Re: Topic on tubes

Post by Doc Holliday »

I have a gut shot of the Ga-20T
Image
This was as it turned up. Since I've cleaned it and am awaiting on arrival of reproduction jensen sticker

The GA-6 came re-capped with orange drops. I've since purchased some NOS Cornell 0.5 and 0.1 caps to replace the orange drops and have it booked in with my amp tech in 2 weeks. According to the schematic it also had 2x electrolytics replaced with the wrong value so I've bought a few F&T caps of correct spec to replace them. Once changed I'll post a gut shot here! :tu:
Thanks for the Tube lesson also it's always great to have an insight before purchase as these 6V6s are creeping up! I've got a 6v6 brimar that I put in my GA-5. It was a little aggressive and boomy in that amp for my taste so I've put a Ken-Rad in and it sounds more pleasing to my ear. With the GA-5 being rather midrangey which is great the Ken-rad adds the clarity and definition.
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Doc Holliday
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Re: Topic on tubes

Post by Doc Holliday »

Image
Caps for GA-6
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superslidetail
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Re: Topic on tubes

Post by superslidetail »

I have some of those Cornells too! :tu:
Orange Haze...it ain't Purple no more...
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Radiotron
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Re: Topic on tubes

Post by Radiotron »

Great write up Waveclipper!.
I really have to start taking notes.

Those Brimars sound like great tubes, will keep an eye out for those.
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Doc Holliday
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Re: Topic on tubes

Post by Doc Holliday »

Those cornells any good ? ^ ordered them in from the states
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waveclipper
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Re: Topic on tubes

Post by waveclipper »

Lovely! I'm sure I've got some Cornells somewhere in my stash but not useful coupling cap values, never tried an Astron either...

Interesting you found the Brimar to be boomy but there you have it - valve tasting is very dependent on the circuit, speaker, other tubes used and preferences of the beholder. Brimars from about the mid 70s onwards I believe were re-labelled Russian tubes (I bought one for a couple of euros out of curiosity) and definitely flat and muddy sounding - nothing like the British made ones. It has jet black completely opaque glass that hides most of the innards with much less of the top mica showing...
My Ken-Rad is very similar to an RCA - great valve :tu:
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Doc Holliday
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Re: Topic on tubes

Post by Doc Holliday »

That sounds like my brimar ^ it did say made in England though so I presumed maybe it was legit?! Maybe not?! I'll post a picture when I'm at home. Out of curiosity I was going to put a matched pair of 50s brimar in the ga-6 to make it more of a mini Marshall. There along the tweed design so I thought I might? And we'll we know the history behind the baseman tweed and the jtm45.
Could probably pickup a matched pair for £70.00. I love those Tungsol nos 6V6s but I am tempted.
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superslidetail
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Re: Topic on tubes

Post by superslidetail »

I haven't used any of the Cornells yet so I have no idea. :lol:
Orange Haze...it ain't Purple no more...
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waveclipper
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Re: Topic on tubes

Post by waveclipper »

These are the real deal British Brimars with it's original 50s box -
100_1349 (450x338).jpg
100_1349 (450x338).jpg (183.33 KiB) Viewed 4299 times
Usually white, orange or yellow print on the base and the 2 x 3 digit codes on the glass. I can't find the Russian one at the minute but pretty sure it had a slightly different 'Brimar' logo on the glass and I think it did say 'made in England' on it!
I have quite a few valves that state 'made in wherever' but most certainly weren't based on the etched codes. A frequently seen example is 'Valvo made in West Germany' EL34 that is actually an XF2 made in Mullard's Blackburn plant.
Something to do with international trade issues where some countries weren't allowed to officially import other certain countries products - so they just put whatever suited on the glass.

£70 for a matched pair?!! Fuck me, I only buy on ebay these days and got that nos matched quad of Canadian Westinghouse 6v6g for €35. I mostly buy tested old stock stuff but one can easily get old used 6v6s for £4-£10 tops. The matched pair of nos 60s RCA 6v6gt clear glass were €13.50 (I got another clear glass from the same guy for €4). I've only got a couple of duds as part of a bigger purchase that were basically untested and a bit of a risk but generally speaking you can get really great stuff dirt cheap!
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Doc Holliday
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Re: Topic on tubes

Post by Doc Holliday »

Hey if you can point me in the right direction for a nos matched pair of brimars cheaper let me know :D
I've got no testing kits here so I generally go with dealers I recognise to make sure they are matched and nos.
I do buy pulls for £5-£10 but for the Gibsons here which require 2x 6v6 I obviously need them matched.
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