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Remember when CDs first came out, many folks felt their sound was cold, harsh and lifeless compared to LPs. And then we really got a bad taste of that when they started mastering them to brick wall levels. Everything gets colored slightly all through the chain right to your speakers and even how your room acoustics absorb or reflect sound. I remember when I first got my Oppo 205 how thin the low end sounded on SACDs compared to my old Denon DVD 3910 (had to make adjustments to cross over and Sub to prop it up.) I believe the DACs in the Oppo are just handling the sound that much differently. I read many a post over at the AVS forum with similar issues.
 
Tubes are neat because they glow! I found the glow of tubes and an LP spinning in a turntable quite mesmerizing back in the day. Now I am mesmerized by the duration bar progressing on the TV screen. :cool:

Yes things are quite different now....I used to love the "glow" of my receiver in a dark room while smoking a joint....now it's a bright room with a chilled bottle of Ensure :whistle:
 
Yes things are quite different now....I used to love the "glow" of my receiver in a dark room while smoking a joint....now it's a bright room with a chilled bottle of Ensure :whistle:

Ensure? Count your blessings Clinty...I can't drink even that stuff because the ingredient malodextrin makes me bloated like a record with way too much bass! Show us your gear!!!!
 
The truth is of course that valves do not of themselves inherently sound bad any more than transistors of themselves inherently sound good. However, there were, and continue to be, good and bad sounding amplifiers built with both technologies. Lots of vintage valve amps were terrible things, badly designed and poorly built with cheap components. But there were a legion of ghastly sounding and shoddily made solid state amps as well. Neither technology holds any magic. Successful achievement of fidelity is wholly a matter of proper engineering. You can build fantastic sounding, high performance amplifiers with either technology if you design and engineer them properly. Although of course there are fewer people around with the knowledge and capabilities to do so in the thermionic domain these days.
Yah what he said
 
And on the subject of properly engineered valve amplifiers...

There's little prospect of a return to the concert hall for the foreseeable future - and sadly, this is the first year that I haven't been to The Proms since 1976!! Forced into staying a home for entertainment, I therefore have an excuse to upgrade the Hi-Fi system! I wanted the best sounding, and best made, valve amp available and the small German brand Octave is very highly regarded in the field these days with innovative new circuit topologies (not just rehashed 1950's stuff). After a lot of research I decided on their most powerful V80SE integrated amp which has had rave reviews worldwide and I've just taken delivery of one now. This shows the weighty beast having just been lugged out of its packing crate but before discarding, as everybody does, the ugly valve cage fitted for health and safety reasons-

Octave 1.JPG


This stuff is hand made in Germany (not China!)-

OCTAVE Production

and was therefore a little on the pricey side (!), but I got an excellent trade in deal for some of my existing equipment. It has loads of features that are fairly unusual these days, particularly on a valve amp, such as recorder in / out, processor loop, pre-amp and power-amp sections operable separately -

Octave 2.JPG


all very useful if, like me, you want to connect things like a digital recorder and of course an SMv2. It also has a remote control milled out of a solid lump of aluminium that weighs 1/4 Kg!

But the main attraction was that the power amp is wholly designed around the new generation of high power valves that have gone into production recently. The following shows the unit as I'm installing KT120 beam tetrodes for initial commissioning. These massive valves, as the name suggests, produce 120W from a push-pull pair-

Octave 3.JPG


I'll also be trying it with the even larger KT150's (which are even scarier!). The great thing is that you can actually use practically any power valve in it because (unlike most valve amps) you can set the optimum operating conditions using a simple LED display on the front panel; just set everything to green when you change valves-

Octave 4.JPG

I got it on sale or return - but even after only a few hours of running in, it won't be going back, it really sounds superb. Valve amps are often praised for being open and natural sounding although honestly often tend to be a bit 'flabby' in the bass - but I'm genuinely shocked at how deep and controlled this thing is - and the amount of power on tap is effectively limitless.

Octave 5.JPG


It is probably the best amplifier, be it valve or solid state that I've ever owned - and that's a lot!
 
And on the subject of properly engineered valve amplifiers...

There's little prospect of a return to the concert hall for the foreseeable future - and sadly, this is the first year that I haven't been to The Proms since 1976!! Forced into staying a home for entertainment, I therefore have an excuse to upgrade the Hi-Fi system! I wanted the best sounding, and best made, valve amp available and the small German brand Octave is very highly regarded in the field these days with innovative new circuit topologies (not just rehashed 1950's stuff). After a lot of research I decided on their most powerful V80SE integrated amp which has had rave reviews worldwide and I've just taken delivery of one now. This shows the weighty beast having just been lugged out of its packing crate but before discarding, as everybody does, the ugly valve cage fitted for health and safety reasons-

View attachment 54648

This stuff is hand made in Germany (not China!)-

OCTAVE Production

and was therefore a little on the pricey side (!), but I got an excellent trade in deal for some of my existing equipment. It has loads of features that are fairly unusual these days, particularly on a valve amp, such as recorder in / out, processor loop, pre-amp and power-amp sections operable separately -

View attachment 54653

all very useful if, like me, you want to connect things like a digital recorder and of course an SMv2. It also has a remote control milled out of a solid lump of aluminium that weighs 1/4 Kg!

But the main attraction was that the power amp is wholly designed around the new generation of high power valves that have gone into production recently. The following shows the unit as I'm installing KT120 beam tetrodes for initial commissioning. These massive valves, as the name suggests, produce 120W from a push-pull pair-

View attachment 54650

I'll also be trying it with the even larger KT150's (which are even scarier!). The great thing is that you can actually use practically any power valve in it because (unlike most valve amps) you can set the optimum operating conditions using a simple LED display on the front panel; just set everything to green when you change valves-

View attachment 54651
I got it on sale or return - but even after only a few hours of running in, it won't be going back, it really sounds superb. Valve amps are often praised for being open and natural sounding although honestly often tend to be a bit 'flabby' in the bass - but I'm genuinely shocked at how deep and controlled this thing is - and the amount of power on tap is effectively limitless.

View attachment 54652

It is probably the best amplifier, be it valve or solid state that I've ever owned - and that's a lot!
Awesome looking unit! And I kinda like the cage on top, gives it a slight Darth Vader look. 120 WPC is amazing for a tube amp as I think the general perception is tube amps usually are good for about 40 watts.
Hmmm, German amp, Russian tubes, and in a British household. Quite diverse!
Edit: Are you still using the Copland with this?
 
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Awesome looking unit! And I kinda like the cage on top, gives it a slight Darth Vader look. 120 WPC is amazing for a tube amp as I think the general perception is tube amps usually are good for about 40 watts.
Hmmm, German amp, Russian tubes, and in a British household. Quite diverse!
Edit: Are you still using the Copland with this?
Looks like you can switch it down to 30W in Ecomode (Is that for smaller speakers use?)
 
Looks like you can switch it down to 30W in Ecomode (Is that for smaller speakers use?)
No, actually "Ecomode" is a sort of auto standby. If it detects that there's been no audio signal for 10 minutes then it shuts down the power amp section but leaves the pre-amp section alive (reducing power consumption to 30W).
 
No, actually "Ecomode" is a sort of auto standby. If it detects that there's been no audio signal for 10 minutes then it shuts down the power amp section but leaves the pre-amp section alive (reducing power consumption to 30W).
Too bad as you could probably use that monster valve amp to heat the room in winter. Congratulations on your acquisition.
 
OK, so I think it’s time to try the KT150 valves now. They came in a big box from Octave and were the set they used in the factory for the amp’s three day burn in test:

kt150_1.JPG


Set the bias to green and away we go…

kt150_2.JPG


Actually I don’t expect there to be any real change in sound from the KT120. There shouldn’t be really – any well designed amp with the bias set correctly should only be using the linear portion of the valve’s transfer curve. They do provide another 30W per channel of power, and whilst that is not very significant in dB terms, it might improve the dynamic headroom even further (sorry neighbours!). They certainly look the part…

kt150_3.JPG
 
OK, so I think it’s time to try the KT150 valves now. They came in a big box from Octave and were the set they used in the factory for the amp’s three day burn in test:

View attachment 54693

Set the bias to green and away we go…

View attachment 54694

Actually I don’t expect there to be any real change in sound from the KT120. There shouldn’t be really – any well designed amp with the bias set correctly should only be using the linear portion of the valve’s transfer curve. They do provide another 30W per channel of power, and whilst that is not very significant in dB terms, it might improve the dynamic headroom even further (sorry neighbours!). They certainly look the part…

View attachment 54695
So... can you tell a difference between the tube types? Any complaints from the neighbors? No? Then you aren't playing it loud enough.

As a general info, for those that like DIY with tubes or solid state here's an interesting website:

http://www.analogmetric.com/index.php
I haven't ordered anything from there , yet, but it's fun to browse.
 
I have two main systems; my “original” is now in the basement in my man cave. Both systems are bi-amped. My Man Cave set up uses tubes for the mid/high and solid state (mos-fet) for the bass.
I call it my “Wall of Tubes”. The entire rack is all homebuilt. The tube amplifiers came about from a design from Acrosound, shown in an old publication supporting their line of Ultra-Linear Output Transformers. Its design was beautifully balanced from input to output, incorporating excellent sounding octal tubes 6SN7 and one 6SL7 in the driver stage. You can find it here. http://www.tubebooks.org/file_downloads/acrosound.pdf
I had previously been given a box full of 6146 transmitting tubes; Acrosound had an amplifier design that used them. I doubt that the specified transformer is available anymore (Acrosound TO-350), it has a separate winding for the screen grid. I didn’t even bother looking for it but opted for a more conventional and readily available Hammond Transformer which is made in Canada! My transformers have a tap for the screen grids rather than a separate winding. The original 6146 design runs 725V on the plate and 220V on the screen grid. I thought that I could make it work with a fixed voltage on the screen grid and running a more conventional 500V on the plate. It would then run as a triode rather than in ultra-linear mode producing much less power but that would still be OK. Well I had trouble getting it to function correctly. I decided to try more conventional output tubes instead, I put in a set of KT-88’s which worked out fantastic. Further refinements included regulating the supply voltage to the driver stages, while leaving the plates unregulated. I tweaked the feedback RC network for best square wave response, and ran feedback around both sides the way that AR does. A switch was added to connect the screen grids such that the amplifier can run in ultra-linear mode or triode mode. Triode mode gives less power but reportedly better sound. The two chassis below contain power supplies for the four amplifiers one for each pair. They contain different transformers but are functionally the same.
The bottom two silver boxes have been in my system since the late seventies. The bottom box contains four +/- 45 Volt power supplies, (quad mono). The smaller box originally contained eight ILP 120W amplifier modules. Four were for bass the other four for mid/high. Latter I add four more IPL modules, they sported mosfet output transistors. They only put out 60W each but sounded better than the bi-polar’s, I used them for the mid/highs. The bi-polar amps were then bridged for even more bass output power.
I used to be able to boast about having a 1200W stereo system! People would say “Oh it must be really loud”, I would have to explain that it’s like having a big V8 in your car; it doesn’t mean that you are going to drive it wide open all the time. It just gives you extra power (headroom) for passing and hill climbing, same with audio. That argument might now carry a bit less weight given the sorry state of today’s overly compressed audio! Given the number of output channels in some of today’s home theatre systems, I’m sure that kind of power is not unheard of though, it adds up fast!
Shortly after becoming a reader of “Glass Audio” and “Audio Amateur” I decided to build “A Sixty Watt Mosfet Power Amplifier” by Erno Borberly
Rack.JPG
TubeAmpFront.JPG
TubeAmpBack.JPG
ly. The project was greatly simplified by purchasing the circuit boards from “Old Colony Soundlab”. The amps sound very good indeed and have proven to be very reliable, over the years. I originally configured them for the mid/high frequencies but now use them for the bass with the tube amps driving the mid/high speakers. The Borberly amps now reside in the smaller silver box in place of the ILP modules. The
Rack.JPG
amps described here were originally part of the Living Room system, due to the size of the tube amps they were placed in the basement. The long feeder lines made the use of balanced interconnects necessary. The amps were/are turned on and off by means of solid state relays and a 12V control wire connection.
 
I have two main systems; my “original” is now in the basement in my man cave. Both systems are bi-amped. My Man Cave set up uses tubes for the mid/high and solid state (mos-fet) for the bass.
I call it my “Wall of Tubes”. The entire rack is all homebuilt. The tube amplifiers came about from a design from Acrosound, shown in an old publication supporting their line of Ultra-Linear Output Transformers. Its design was beautifully balanced from input to output, incorporating excellent sounding octal tubes 6SN7 and one 6SL7 in the driver stage. You can find it here. http://www.tubebooks.org/file_downloads/acrosound.pdf
I had previously been given a box full of 6146 transmitting tubes; Acrosound had an amplifier design that used them. I doubt that the specified transformer is available anymore (Acrosound TO-350), it has a separate winding for the screen grid. I didn’t even bother looking for it but opted for a more conventional and readily available Hammond Transformer which is made in Canada! My transformers have a tap for the screen grids rather than a separate winding. The original 6146 design runs 725V on the plate and 220V on the screen grid. I thought that I could make it work with a fixed voltage on the screen grid and running a more conventional 500V on the plate. It would then run as a triode rather than in ultra-linear mode producing much less power but that would still be OK. Well I had trouble getting it to function correctly. I decided to try more conventional output tubes instead, I put in a set of KT-88’s which worked out fantastic. Further refinements included regulating the supply voltage to the driver stages, while leaving the plates unregulated. I tweaked the feedback RC network for best square wave response, and ran feedback around both sides the way that AR does. A switch was added to connect the screen grids such that the amplifier can run in ultra-linear mode or triode mode. Triode mode gives less power but reportedly better sound. The two chassis below contain power supplies for the four amplifiers one for each pair. They contain different transformers but are functionally the same.
The bottom two silver boxes have been in my system since the late seventies. The bottom box contains four +/- 45 Volt power supplies, (quad mono). The smaller box originally contained eight ILP 120W amplifier modules. Four were for bass the other four for mid/high. Latter I add four more IPL modules, they sported mosfet output transistors. They only put out 60W each but sounded better than the bi-polar’s, I used them for the mid/highs. The bi-polar amps were then bridged for even more bass output power.
I used to be able to boast about having a 1200W stereo system! People would say “Oh it must be really loud”, I would have to explain that it’s like having a big V8 in your car; it doesn’t mean that you are going to drive it wide open all the time. It just gives you extra power (headroom) for passing and hill climbing, same with audio. That argument might now carry a bit less weight given the sorry state of today’s overly compressed audio! Given the number of output channels in some of today’s home theatre systems, I’m sure that kind of power is not unheard of though, it adds up fast!
Shortly after becoming a reader of “Glass Audio” and “Audio Amateur” I decided to build “A Sixty Watt Mosfet Power Amplifier” by Erno BorberlyView attachment 58341View attachment 58342View attachment 58343ly. The project was greatly simplified by purchasing the circuit boards from “Old Colony Soundlab”. The amps sound very good indeed and have proven to be very reliable, over the years. I originally configured them for the mid/high frequencies but now use them for the bass with the tube amps driving the mid/high speakers. The Borberly amps now reside in the smaller silver box in place of the ILP modules. The View attachment 58341amps described here were originally part of the Living Room system, due to the size of the tube amps they were placed in the basement. The long feeder lines made the use of balanced interconnects necessary. The amps were/are turned on and off by means of solid state relays and a 12V control wire connection.
That’s clearly a very impressive setup you have there. Please tell us about your experience with tube rolling and replacing and bias matching tubes. I would imagine that it can get quite warm down there.
 
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