6 Channel amp - behind the scenes test

Help Support QuadraphonicQuad:

Soundfield

1K Club - QQ Shooting Star
Joined
Dec 29, 2011
Messages
1,438
Location
Essex, UK
who'd have thunk????
Russia!!!
wonder why it's not made in China... like everything else in this plane of existence...
The main Russian plants are owned by an American.
The Chinese produce a huge amount of valves. Of lot of it is cheap rubbish. They do have small number of 'boutique' manufacturers that produce higher quality stuff but that sells for outrageous prices.
 

gene_stl

400 Club - QQ All-Star
QQ Supporter
Joined
Nov 3, 2019
Messages
474
Location
St.Louis
Soundfield , does it not offend you that they have appropriated the (most venerable) Genalex brand name for Russian tubes. And I am not even British.
Genalex used to be General Electric of Britain and their Gold Lion KT88 MPs were the best you could get. When they became difficult to get here is when I made the switch to solid state. About 1973 or so. iirc.

I really hate it when somebody (perfectly legally) buys a brand name and recycles it. You aren't getting the same thing no matter what. I don't even care if they are actually better which I concede is a possibility since the soviets used tubes in their military equipment for a long time. It is much more EMP resistant than some solid state gear. But I am in favor of calling a Sovtek a Sovtek. There are many other situations like this that "set me off" Like
"Leica" microscopes. There never was any such thing.
 

kfbkfb

701 Club - QQ All-Star
QQ Supporter
Since 2002/2003
Joined
Feb 20, 2003
Messages
794
Location
Midwest USA
Can the 6 channel amp drive "difficult" loads (electrostatic speaker for example).


Kirk Bayne
 

chucky3042

1K Club - QQ Shooting Star
Joined
Apr 9, 2012
Messages
1,941
............. Speaking of valves, one of the nice things they offer is soft clipping. Well today Bitch and myself were running the mini brute on a bunch of difficult loads including 2 subwoofers, 2 electrostatics and 2 4 Ohm coil based conventional speakers (actually concentric bipoles!) and driving the lot well into deep clipping. Incredible loud stuff.

The remarkable thing was the clip was not very noticeable, yes you could tell but it was not the usual hash raspy sound. The average Joe might in fact not notice it.

Also after running a bunch of torture tracks finishing off with Brian Setzers "town without pity" (we call it the track without pity) the unheatsinked class D chip temperatures was just under 50 degrees C.

No smoke!!!!
 

DuncanS

2K Club - QQ Super Nova
QQ Supporter
Joined
Aug 30, 2012
Messages
6,195
Location
UK
:sneaky: the number of people who don't realise electronics runs on smoke, so when it escapes ........ :ROFLMAO:


My worst case was my first ever switch mode PSU design to allow us to test another board when the bipolar transistor (before cheap MOSFET days!) plastic casing bubbled for a while ................................. then the :smokin smoke escaped!
 

gene_stl

400 Club - QQ All-Star
QQ Supporter
Joined
Nov 3, 2019
Messages
474
Location
St.Louis
I once built a stereo preamp kit in one sitting. I was too tired at the end and despite knowing better installed one of the power supply electrolytics backwards. I switched it on and the cap splurped all over the board. with a complete escape of smoke. It was the week end so I had to wait until monday to get to the electronics store and buy a replacement. (Back when we actually HAD SEVERAL electronics stores . Gone are THOSE days). Then it worked perfectly except it sounded awful and I got rid of it fast. (It was a Southwest Technical Products preamp. circa 1971)



Even in 1971 that price was fantastic!
 
Last edited:

Sonik Wiz

2K Club - QQ Super Nova
QQ Supporter
Joined
May 30, 2005
Messages
2,671
Location
Kansas City
I once built a stereo preamp kit in one sitting. I was too tired at the end and despite knowing better installed one of the power supply electrolytics backwards. I switched it on and the cap splurped all over the board. with a complete escape of smoke. It was the week end so I had to wait until monday to get to the electronics store and buy a replacement. (Back when we actually HAD SEVERAL electronics stores . Gone are THOSE days). Then it worked perfectly except it sounded awful and I got rid of it fast. (It was a Southwest Technical Products preamp)
Haha etc!

Back in my early teens when I was building my DIY skills by building stuff, one project was a single ch color organ. Operating from line current. When I plugged it in a high current SCR exploded like a fire cracker! My next project was the SSS: Scared Shitless Shield. It was a 4'x4' sheet of plexiglass on a frame that I could stand behind & turn on power to whatever project from across the room.
 

Soundfield

1K Club - QQ Shooting Star
Joined
Dec 29, 2011
Messages
1,438
Location
Essex, UK
When I was an electronics apprentice we were ‘offered the opportunity’ to work in the High Voltage Test department. Whenever something like a faulty 50kV power supply need to be switched on it was always one of us lucky apprentices who were ‘allowed’ to do it. It was thought to be character building. Those who had already had their characters built of course retreated to a safe distance.
 

kfbkfb

701 Club - QQ All-Star
QQ Supporter
Since 2002/2003
Joined
Feb 20, 2003
Messages
794
Location
Midwest USA
Is the tech behind this soft clipping class D amp patentable?

Can this 6 channel amp output its maximum power to all 6 channels at the same time?


IIRC, many MCH receivers (5.1 and above) can't provide their full rated power with all channels driven, here's just an example (nothing against Marantz):
^^^
...140 watts of power per channel (8 Ohm, 20Hz-20kHz, THD: 0.05%, 2ch driven)


Kirk Bayne
 

gene_stl

400 Club - QQ All-Star
QQ Supporter
Joined
Nov 3, 2019
Messages
474
Location
St.Louis
The limitation is frequently too many channels and not enough power supply horsepower. A channel can provide full power if it is the only one driven but when you start driving multiples the power supply runs out of steam. I think the six channel supply comes with something like a 160 watt supply (seems like it was 32 volt 5 amp) but I think it might be able to be hooked up to something that can deliver more volts and more amps. Chucky could shed light on that.
 

chucky3042

1K Club - QQ Shooting Star
Joined
Apr 9, 2012
Messages
1,941
The limitation is frequently too many channels and not enough power supply horsepower. A channel can provide full power if it is the only one driven but when you start driving multiples the power supply runs out of steam. I think the six channel supply comes with something like a 160 watt supply (seems like it was 32 volt 5 amp) but I think it might be able to be hooked up to something that can deliver more volts and more amps. Chucky could shed light on that.
Hi
All good comment. Music is a funny thing, it rarely happens all at once and at full magnitude so yous the 120 W per channel is a peak thing but in fact the limitation is the power supply which in our case is 30 V and 10 Amps = 300 W operating into a 95% efficient class D. The structure of this little beast is capable of doing all 6 at once but you will need a bigger power supple (and connector).
 

chucky3042

1K Club - QQ Shooting Star
Joined
Apr 9, 2012
Messages
1,941
Is the tech behind this soft clipping class D amp patentable?

Can this 6 channel amp output its maximum power to all 6 channels at the same time?


IIRC, many MCH receivers (5.1 and above) can't provide their full rated power with all channels driven, here's just an example (nothing against Marantz):
^^^
...140 watts of power per channel (8 Ohm, 20Hz-20kHz, THD: 0.05%, 2ch driven)


Kirk Bayne
Hi Kirk
It's not patentable as we are using the
TPA3244 60 W stereo chip in parallel mode making 120 W per channel. Meaning 6 of these chips. I claim we have done a particularly compact short path length design observing SMPS conventions.

The 60 W continuous is capable of peaking up tp 110W. Just a nice solid chip that we cannot beat or fault!
 

Sal1950

800 Club - QQ All-Star
QQ Supporter
Joined
Jan 3, 2020
Messages
880
Location
Central FL
In a Kansas City suburb (Lee's Summit) there was a huge Western Electric plant. By huge I mean it looked like a ranch style castle made out of lime stone. It shut down in the late 70's. Then in the mid 80's part of it was opened & rented out for the production of vacuum tubes, mostly for audio. I know Kustom guitar amps were a big customer. So that ran for about 10 years & fizzled out. That's last I know of for American production of tubes.
That (Western Electric branch) company has been in continuous operation making 2 or 3 moves of the plant over the last few decades. Building 300B triodes and other tubes for US DOD, they just announced their latest 300B in October of last year, currently being built in Rossville GA USA.
Info courtesy of Stereophile's Herb Reichert in this months (Aug) Gramophone Dreams.
 

gene_stl

400 Club - QQ All-Star
QQ Supporter
Joined
Nov 3, 2019
Messages
474
Location
St.Louis
Of course this is the classic case of someone buying a trademark. The real Western Electric went out of business between 1984 and 1996.
The current company using the name mainly exists to relieve audiophiles of their money. Just say no.
They were in the telephone and telegraphy business. Audio and movie speaker systems were a small sideline.
 
Top