• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

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Bass Horneman,

Great looking 3 channel amp!

Could be used for L+R woofer, and L & R mid tweets.

Or, could be used with 3 full range speaker systems and 3 channel stereo from an SACD player.

Ooops, I clicked on the first 10 postings on this old thread, thus the comments on Bas Horneman's amp
 
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During my last build (SE 300B) I made a promise to myself I am not flipping an amp over and over anymore

like this?

I'm not taking a PCB out any more over and over....
 

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KT150 Single Ended

Hi all, here are the photos of my last project.
KT150 single ended, 6CG7 input and 6N1P driver, 18 Watt with a 15 Hz - 45 KHz bandwidth.
After many attempts in housing tube amps into any sort of cases, I've decided to go naked by using a wooden base and a metal cage on top. Actually the metal cage is on the way.

Danilo
 

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I’m enjoying seeing all the alternatives people come up with to the standard amp-on-a-plate-with-a-wooden-skirt. I know it’s the most practical approach on one level but the breadboard landscape (above) has its value too. A year from now I hope to post, should the gods allow, a type I’ve not seen here yet. It’s a great time to stay home and keep busy.
 
I’m enjoying seeing all the alternatives people come up with to the standard amp-on-a-plate-with-a-wooden-skirt. I know it’s the most practical approach on one level but the breadboard landscape (above) has its value too. A year from now I hope to post, should the gods allow, a type I’ve not seen here yet. It’s a great time to stay home and keep busy.
I think it was an article in Glass Audio back in 2004 ... 2006, describing a sort of building block/breadboard idea when designing amps. Having input tubes, phasesplitters, driver, output tubes, transformers each on its own "board", just to hook up for a desired design.
 
Hi all, here are the photos of my last project.
KT150 single ended, 6CG7 input and 6N1P driver, 18 Watt with a 15 Hz - 45 KHz bandwidth.
After many attempts in housing tube amps into any sort of cases, I've decided to go naked by using a wooden base and a metal cage on top. Actually the metal cage is on the way.

Danilo

Ciao Danilo,

very nice idea love it, please post picture when is finished, what about the cage, did you buy it already done or you made it? all the best..:)
 
Building proces of a VT25 ultrapath amp.

Hello,
Here some pics of a stereo VT25A DRD amp.
Power supply is the biggest part. Choke input, after the first cap each channel has its own LCRC circuit. Second choke is a Lundahl connected in what they call common mode but i got the advice to use that only for the input choke. So now i am going to rearrange the cables for the return all to one point close to the first pair ( CSI caps from ebay) Greetings, Eduard
 

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all tube graphic EQ

I am at home for 30 days for this virus so lots of time, so I decide to give it a go to the Rickard Berglund design.

I already order most of the components moths ago, still waiting the power transformer from Antek and the 3U rack mount cabinet all bought in US so I really do not know when they will arrive here in Philippines with this crisis, so with all I have and using a power transformer used for a tube amp I start the project.

I finish the project on paper and assembling all components, this became also more complex because I add to the Berglund design a led display for every single frequencies so when finish I will have the exact idea of the equalisation.

I used 6N2P instead the 12AX7 but when finish I will replace with 6N2P-EV, also on the way, so I put all on a wooden board connect everything unfortunately with a not really good wire but is the only one available at the moment, so I was expected a not so good result or some not pleasant noise but with surprise when I put on the EQ all work very good and the sound is really amazing, no oscillation at all, just a little hum at the max vol of the amp, so I am extremely happy with the result so now looking forward to receive the missing component and cabinet for finalise this project, I still do not know how I will be able to do 100 perfect holes on the front panel of the cabinet but well will see :).

The sound test was very good so next I will make some serious test with generator and scope and Rew, for the main time some pic of the EQ.
 

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I'm very interested in the LED display. Could you please share the schematic? Thanks. :D

I am at home for 30 days for this virus so lots of time, so I decide to give it a go to the Rickard Berglund design.

I already order most of the components moths ago, still waiting the power transformer from Antek and the 3U rack mount cabinet all bought in US so I really do not know when they will arrive here in Philippines with this crisis, so with all I have and using a power transformer used for a tube amp I start the project.

I finish the project on paper and assembling all components, this became also more complex because I add to the Berglund design a led display for every single frequencies so when finish I will have the exact idea of the equalisation.

I used 6N2P instead the 12AX7 but when finish I will replace with 6N2P-EV, also on the way, so I put all on a wooden board connect everything unfortunately with a not really good wire but is the only one available at the moment, so I was expected a not so good result or some not pleasant noise but with surprise when I put on the EQ all work very good and the sound is really amazing, no oscillation at all, just a little hum at the max vol of the amp, so I am extremely happy with the result so now looking forward to receive the missing component and cabinet for finalise this project, I still do not know how I will be able to do 100 perfect holes on the front panel of the cabinet but well will see :).

The sound test was very good so next I will make some serious test with generator and scope and Rew, for the main time some pic of the EQ.