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Hybrid bipolar amp

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Hi all

The best wishes for 2011 and make the best and most nice sounding amp who last for a livetime in stead of a trow away amp from china destroying our worlds nature as with many products
we don,t need.

Here I have a schematic of my own design who is not ever build or tested I thought this is nice for the people here to play with.

You need multisim 11 for it. the simulation was nice it is current feedback type of amp with a (high current) tube in mustage form driving the transistors, it is not a mosfet amp, bipolairs sound far better if good used, never try IGBT she are far worse then the mosfet, mosfet with his miller capacity have to be drive with current, a lot of it, most 100 ma to sometimes 300 ma that is big class a for a driver stage and it has to make also heavy voltage the same time, bipolairs use current only that is nice.

try it and let me now, I work myself on the design it is a new way of use tubes with bipolairs, and maybe i are completely wrong and blow up the bipolairs with the tube while warming up haha.
 

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No, there's no hybrid forum. It seems that there are a few people who visit both the SS and tube forum and can contribute to hybrid amplifier threads, but not many. I have wondered if it's not better to present the tube part on the tube forum and the SS part in the SS forum in order to attract some input.

Anyhow, your amplifier sounds interesting - can you post a schematic diagram, I don't have multisim.
 
Here it comes..
 

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Here the instruments, be aware it is only simulation, you have to fine tune it, but it is nice to try a tube driving bipolairs, it is with feedback bipolairs can,t without as power amp.

the tube driver is a mu-stage with a very low impedance because of the mosfet used. the tube has to be operated at 10 ma, so if build fine tune it.
 

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I can't see the point of this sort of hybrid, as it combines the worst features of both technologies and requires a complex multi-rail power supply. Don't expect "tube sound" from it!

Hybrides never can give sound like tubes, tube amps are lazy amps, not much speed, unless you use a very expensive output trafo.

I have a hybride with 6C4N and as mosfet driver 6C19N a very beefy triode.

It sounds very good, Much people here have heard it. but afcourse not so sweet as a real tube amp, that is not possible because there is no output trafo who slow down signals making blockwaves sinuslike. Tube amps can sound beautifull because of the rest she give to music, speed is not really a isseu there.
 
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I find the music comes out of my valve amp at the same "speed" as it goes in. My amp is not "lazy"; it works quite hard.

I don't like "tube sound" myself, but I wondered if that is what you are pursuing. The 6C4 input stage will add a little second-order distortion, which will then get mixed up to higher orders by the negative feedback. The net result won't be much different from an all solid-state amp, as the dominant distortion will come from the output stage.

"Hybrid SRPP" would impress some people in an advert for a Chinese amp on ebay, but why copy them in a DIY design?
 
I find the music comes out of my valve amp at the same "speed" as it goes in. My amp is not "lazy"; it works quite hard.

I don't like "tube sound" myself, but I wondered if that is what you are pursuing. The 6C4 input stage will add a little second-order distortion, which will then get mixed up to higher orders by the negative feedback. The net result won't be much different from an all solid-state amp, as the dominant distortion will come from the output stage.

"Hybrid SRPP" would impress some people in an advert for a Chinese amp on ebay, but why copy them in a DIY design?

Haha you are a tube fan? that,s nice because I love the nostalgie around them, it is not for nothing that i try to combine them, Yes the tube amps has a warm and relaxed sound, and I don,t want to drop tube lovers, I like to play with tubes, the design with bipolairs I have put here because this is very rare, the most are mosfets, but the miller capacity is sometime a problem with mosfets, bipolairs are a lot better, I have included a schematic (mosfets) I use now, it is not completely the same, I use a beefy EL84 for driving the mosfets with a mosfet CCS and get rid of the capacity for now. The new schematic uses a white follower for the mosfets with two low voltage 6C19 tubes who are very beefy x two (white follower).

It is not distortion but the lazyness from the output trafo, mosfets are much faster, and that give more detail, if very good designed, that SRPP thing is not good sounding, SRPP load the bottom tube to much and therefore not much freedom, with a mustage or a CCS there is mucho impedance so the bottom tube see a very big pipe and can swing freely and that all with a low impedance..

But tja it is al theory you have to play that is wat this forum is about.

Excuses for the schematic sometimes a little to quick made.
 

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quiet here? not much men who like challances.

oke here a plot of the hybride wiith dual mu-stage dc coupled to the mosfets with current feedback and tube age tracking opamp who do also offset, cuurent feedback is local and the current feedback makes the amp bandwith independent of feedback and very fast, here the tube has a lot of beef, you can use a other bigger one with a max mu of 4 now it is 2, so the feedback is weak.
 

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I can't see the point of this sort of hybrid, as it combines the worst features of both technologies and requires a complex multi-rail power supply. Don't expect "tube sound" from it!

There is no reason why the tube cant run off bipolar B+ and B-.
The heater can be dropped off B+ or B- with resistors.

I designed a similar amp and have had good feedback from users.
 
There is no reason why the tube cant run off bipolar B+ and B-.
The heater can be dropped off B+ or B- with resistors.

I designed a similar amp and have had good feedback from users.

most high end has separated B+ and B- but here because of the high suppression of rail noise it is indeed a way to do it.

the tube can work on fairly low supply but better is not lower then 100 volt then you need a separate supply, the tube gets a half of total B volt.
 
"Haha you are a tube fan? " uuuh!? this is the Tubes forum......

I think it is interesting with SS people visiting and challenging our "beliefs" but when you throw out things like "lazy" amps you need to understand that most people here (AFIK) are not into tube amps for the high low order harmonics and low damping factors of poorly designed tube gear (tube sound?)
For the sake of interesting discussions you need to be more clear on what you mean with "lazy" and "speed"
 
I now what the struggle means between bilopair and tube lovers, I like the sound of tubes, but it has no point to struggle about the ja,s or no,s of it, I try to get a combi for tube and bipolair and it is possible to get good sound, but yes oneven harmonic distortion is not a lovely sound, and so tube power stages has here a big plus, only damping is less, also impulse , as we have these days much better outputfrafo,s for tubes wich are much faster tubes as power stages is more interesting.
 
Hi All

a update I have build one and have very good results, i post pictures of the amp, the sound is very nice a tube fan from a store here has a positive word about it, still the sound is more harsh then tubes, that is what I mean with speed or laze, both has its own trouble, why a higher speed then music wants, more important bandwith because of music has a lot more spectrum then many now.

Oke this hybride works now with vertical mosfets as a power stage, dc coupled on driver tubes, the scope pictures are made this afternoon, picture one has square wave on 20 Khz, two has 20 Khz with input filter and the last is a sweep between 10 and 25 Khz, it looks very nice for me, no overshoot.

I am not much here, my friend has proberly lung cancer, that is a big happening for me, and I am try to help coming days but sometimes I have to unload myself with amps and music..
 

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