12B4A SET another approach

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12B4A SET another approach

Postby EWBrown » Mon Dec 29, 2014 4:25 pm

Last edited by EWBrown on Sun Jan 04, 2015 2:15 pm, edited 1 time in total.
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Re: 12B4A SET another approach

Postby Geek » Mon Dec 29, 2014 6:51 pm

Cuties! :))

Now to replace that Hammond with some GXSE and away we go O:)

(This post was NOT paid for by the Weston family ;) )
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Re: 12B4A SET another approach

Postby soundbrigade » Tue Dec 30, 2014 11:29 am

I have tried that one out once. Couldn't get the hum out and found it annoying to drop 150V and some milliamps.
However I think I have found some other schematics using the 12B4A.

This one is coming from Holland (and most propably from diyaudioprojectsforum. It could have been specially made for a friend in Holland:
http://www.pastisch.se/HF/12B4A%20amp.jpg

LED-bias for the driver tube:
http://www.pastisch.se/HF/12b4a_LED_SE.jpg

From Chian or Japan??:
http://www.pastisch.se/HF/5965dc12B4.jpg
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Re: 12B4A SET another approach

Postby Shannon Parks » Sat Jan 03, 2015 10:40 am

Points for using a triode strapped 6AU6! It's a terrible shame that no one makes a new supply for the 12B4, or I'd try to produce a commercial headphone amp with them.

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Re: 12B4A SET another approach

Postby Geek » Sat Jan 03, 2015 1:04 pm

Shannon Parks wrote:It's a terrible shame that no one makes a new supply for the 12B4, or I'd try to produce a commercial headphone amp with them.


Indeed!

Doesn't a triode strapped 6P43P-E or something come close? (???)
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Re: 12B4A SET another approach

Postby Shannon Parks » Sat Jan 03, 2015 3:08 pm

Geek wrote:
Shannon Parks wrote:It's a terrible shame that no one makes a new supply for the 12B4, or I'd try to produce a commercial headphone amp with them.


Indeed!

Doesn't a triode strapped 6P43P-E or something come close? (???)


By Jove, Geek! That tube wasn't on my radar, but it sure looks like a 12B4-type: http://www.klausmobile.narod.ru/testerf ... clones.htm

Image

The curves look almost identical, with great low voltage perveance characteristics. I'll buy some of these for sure. Thanks for the heads up!

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Re: 12B4A SET another approach

Postby Geek » Sat Jan 03, 2015 9:21 pm

It would kick butt in a line stage :))

http://geek.scorpiorising.ca/GeeK_ZonE/ ... pic=4156.0

*edit*

A caveat with these is they LOVE to become V/UHF transmitters (sick) Snub wisely.
(playing with one on the breadboard, it broke the squelch on a 470 MHz FRS radio I forgot I left on)
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Re: 12B4A SET another approach

Postby Shannon Parks » Sun Jan 04, 2015 9:56 am

Geek wrote:It would kick butt in a line stage :))

http://geek.scorpiorising.ca/GeeK_ZonE/ ... pic=4156.0


Good stuff! Ahead of the "curve" as usual.

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Re: 12B4A SET another approach

Postby kheper » Mon Jan 05, 2015 5:24 am

"What the hell am I going to use a 1.5 watt amplifier for?" Guitar amp?

$149 VT-1 1W guitar amp.
http://wangs-amps-usa.myshopify.com/pro ... -amplifier

If you put a gain pot before the 12B4A output tube, it should sound better than a pedestrian12ax7?
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Re: 12B4A SET another approach

Postby soundbrigade » Mon Jan 05, 2015 9:52 am

Some years ago I was very much into STC type of amps (Google Super Triod Connections) and even built twwo amps based on ECL82/6BM8.
There as one site where there were a huge number of designs using various kinds of tubes and one of the designs used a 12B4A together with 12AT7 and a 6AS6. Maybe I should look into this design again as I have transformers and tubes (should still have some 12B4A left).

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Re: 12B4A SET another approach

Postby Geek » Mon Jan 05, 2015 3:18 pm

kheper wrote:"What the hell am I going to use a 1.5 watt amplifier for?" Guitar amp?

$149 VT-1 1W guitar amp.
http://wangs-amps-usa.myshopify.com/pro ... -amplifier


If he wants to sell that as a guitar amp, it's already accompanied by the hashtag of "FAIL" - look at all the HiFi components and HiFi thinking gone into it :/
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Re: 12B4A SET another approach

Postby kheper » Tue Feb 03, 2015 7:42 pm

Geek wrote:
kheper wrote:"What the hell am I going to use a 1.5 watt amplifier for?" Guitar amp?

$149 VT-1 1W guitar amp.
http://wangs-amps-usa.myshopify.com/pro ... -amplifier


If he wants to sell that as a guitar amp, it's already accompanied by the hashtag of "FAIL" - look at all the HiFi components and HiFi thinking gone into it :/


I think I meant that the 12B4A (as the output tube) might make for a better sounding guitar amp than the 12ax7 - with the necessary changes made to his circuit - no stereo, no Hi-Fi components, etc. That puny Wang Amp is popular.
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