Tube amplifiers

[newlash09]

Hi Dakchi..... spent sometime on the net reading articles. As per them, tube-buffers can be used in the under mentioned sequence :

1. Source - tube buffer - preamp ( Ex : turntable - phonostage - tube buffer - preamp or line in of integrated amp )

2. In some integrated amps, there is provision for using a tube buffer or Digital signal processor or equaliser between the pre-amp and poweramp section, through the 'tape-in / tape out' or 'loop in / loop out' terminals.

From the specs of the CXA-80, there is sadly no provision for tape or loop in / outs. So, you cannot introduce a tube buffer between your pre-amp and poweramp sections of the CXA-80. So, the only option is to use it between your source and line-in on the CXA-80.

Again from the net, the 'Yaqin SD-CD3' is getting rave reviews, and is available on amazon usa site for $180/-. And even the manufacturer is stating to place the same between your solid state sources and amplifier. And i guess you can improve the sound for not too much money by changing the tubes. All the best...and please do let us know how you get on.....

( On an other note, some people are using tube buffers between seperate pre-amp and poweramps , to match the output and input impedence of the pre-amp and the poweramp )

 

[DocG]

I'm confused now, dakchi. In your OP you mention the CXA80, while your sig features a PM-6005. What's your actual set-up?

 

[ellisdj]

2 questions on valves Power Amps - how bright do they glow?

- how hot do they actually get?

 

[Gazzip]

2 questions on valves Power Amps - how bright do they glow?

- how hot do they actually get?

Hot and quite bright...

https://i0.wp.com/www.bartola.co.uk/valves/wp-content/uploads/2012/07/IMG_3067.jpg

 

[ellisdj]

Hotter than a stupid hot bryston?

Light could be more of an issue though hmmmm

 

[Al ears]

Hotter than a stupid hot bryston?

Light could be more of an issue though hmmmm

Mine doesn't glow as is enclosed by ventilated casing.

It does get quite warm however, haven't actually measured temperature, but you wouldn't want to leave your hand on it for long, it does require space around it particularly above. You wouldn't want to put it in your average rack.

 

[Gazzip]

Hotter than a stupid hot bryston?

Light could be more of an issue though hmmmm

Mine doesn't glow as is enclosed by ventilated casing.

It does get quite warm however, haven't actually measured temperature, but you wouldn't want to leave your hand on it for long, it does require space around it particularly above. You wouldn't want to put it in your average rack.

Ellisdj's listening room has an AV bias and is jet black. I am talking two miles underground in a cave black. Any glow I would have thought may be an issue if it is located on the front wall near the screen.

The power supply stage of my tube pre-amp lights up like a christmas tree, so I would be surprised if most tube power amps don't glow a little bit in the dark. Enough to distract film viewing...

 

[paulkebab]

my amp doesn't glow enough to be a distraction although the front window revealing one of the valves has a variable brightness LED array which can knock your eyes out. Mine's in a unit with the recommended space all round so I don't get any upward-shining probs. Heat output is.. hot.

 

[dakchi]

Hi Dakchi..... spent sometime on the net reading articles. As per them, tube-buffers can be used in the under mentioned sequence :

1. Source - tube buffer - preamp ( Ex : turntable - phonostage - tube buffer - preamp or line in of integrated amp )

2. In some integrated amps, there is provision for using a tube buffer or Digital signal processor or equaliser between the pre-amp and poweramp section, through the 'tape-in / tape out' or 'loop in / loop out' terminals.

From the specs of the CXA-80, there is sadly no provision for tape or loop in / outs. So, you cannot introduce a tube buffer between your pre-amp and poweramp sections of the CXA-80. So, the only option is to use it between your source and line-in on the CXA-80.

Again from the net, the 'Yaqin SD-CD3' is getting rave reviews, and is available on amazon usa site for $180/-. And even the manufacturer is stating to place the same between your solid state sources and amplifier. And i guess you can improve the sound for not too much money by changing the tubes. All the best...and please do let us know how you get on.....

( On an other note, some people are using tube buffers between seperate pre-amp and poweramps , to match the output and input impedence of the pre-amp and the poweramp )

Thank you for all this information. The remaining issue is that my source is chromecast audio that is connected to the amp through a mini toslink-toslink cable. The tube buffer has a stereo input. It will force me to use a jack 3.5 to RCA cable and I will have to use the internal DAC of chromecast audio which is not good compared to the DAC of my cambridge amp. I will definitely lose quality

 

[ellisdj]

Its interesting - the appeal of tube amplifiers was to approach a more refined sound. Do they or dont they provide refinement over solid state?

I then started to look at the dimension of the units - why are they all so deep 500cm + deep for the higher powered ones

Then they glow bad for a bat cave and get hot - in a heavily insulated room that converts a lot of sound energy into heat, that has a projector that has a ridiculous hot bulb. It might not be a possibility even for consideration (not imminent anyway just a thought)

 

[Al ears]

Its interesting - the appeal of tube amplifiers was to approach a more refined sound. Do they or dont they provide refinement over solid state?

I then started to look at the dimension of the units - why are they all so deep 500cm + deep for the higher powered ones

Then they glow bad for a bat cave and get hot - in a heavily insulated room that converts a lot of sound energy into heat, that has a projector that has a ridiculous hot bulb. It might not be a possibility even for consideration (not imminent anyway just a thought)

It would appear from your concerns that you can forget valve amplification of any sort.

 

[Gazzip]

Its interesting - the appeal of tube amplifiers was to approach a more refined sound. Do they or dont they provide refinement over solid state?

I then started to look at the dimension of the units - why are they all so deep 500cm + deep for the higher powered ones

Then they glow bad for a bat cave and get hot - in a heavily insulated room that converts a lot of sound energy into heat, that has a projector that has a ridiculous hot bulb. It might not be a possibility even for consideration (not imminent anyway just a thought)

A lot of enthusiasts accept the "compromise" of using a valve preamplifier and solidstate power amplifier. I personally do not think this to be a compromise at all given that you get all of the valve good (effortless, rich midrange and sweet treble) with none of the valve bad (tonnes of heat and troublesome, bloaty McBloat bass).

I heard an Audio Research Reference 6 feeding a pair of Reference 750 SE valve monoblocks some time ago. The monoblocks weighed in at £60K for the pair and I thought that they sounded no better than a pair of solidstate monoblocks at 20% of that price. The fact that the guy doing the demo kept proudly drawing comparisons with how close to solidstate power amplification it sounded said it all to me.

If you want to go valve and yet still maintain some power/punch without spending 10's of thousands then buy a good valve pre amplifier and stick it up a solid state power amplifier.

 

[ellisdj]

Horses for courses - all bass power and punch in my system wont come from the valves. Cant have a valve preamp av processor.

It would be worth the hassle of major setup changes and getting clever with light blocking for a better overall mid range and treble - if thats what you get? Probably not but it just got me interested for some reason, never has before.

 

[Gazzip]

Horses for courses - all bass power and punch in my system wont come from the valves. Cant have a valve preamp av processor.

It would be worth the hassle of major setup changes and getting clever with light blocking for a better overall mid range and treble - if thats what you get? Probably not but it just got me interested for some reason, never has before.

You can if you buy a valve pre amplifier with HT bypass. You would simply run your front two channel outputs from your AV processor in through the valve pre amplifier's HT bypass. That's what I do with my Ref 6 to get the PMC's to also work as my front L & R with my AV amp.

 

[ellisdj]

That would mean 2 lots of pre-amplification ?

 

[Gazzip]

That would mean 2 lots of pre-amplification ?

Yep. One for two channel music and one for AV/Multi-channel, both using your Bryston power amplification and Kef front channels...

 

[ellisdj]

I dont understand how that works Gazzip mate - the output from my processor has already been preamplified so it would be feeding a preamplified signal to a pre amplifier?

There is no bypass in my processor to skip anything and I needs its bass management facility / crossover

No way of seperating it mate for me?

 

[Gazzip]

I dont understand how that works Gazzip mate - the output from my processor has already been preamplified so it would be feeding a preamplified signal to a pre amplifier?

There is no bypass in my processor to skip anything and I needs its bass management facility / crossover

No way of seperating it mate for me?

Mine is the same. You run your AV pre amplifier's front left and right channel outputs in to the valve pre amplifer's HT bypass inputs. HT bypass is a straight passthrough to your front left and right speakers, so no further preamplification takes place of the AV signal.

 

[ellisdj]

So your literally doing that just for its valve output stage to put a valve tang on the sound?

I thought I was a nutty audiophile

 

[Gazzip]

So your literally doing that just for its valve output stage to put a valve tang on the sound?

I thought I was a nutty audiophile

2-channel is my hobby and the AV is secondary. I am doing it so that I can enjoy my 2-channel, valve preamplified system, while at the same time I can still use my big PMC's for AV. Make sense?

HT bypass is essentially a switch which allows me to share my front speakers and their mono-block power amps between two separate pre-amp setups.

 

[ellisdj]

LOL sorry Gazzip I am being thick here - I am sorry I cant get my head around it. I wish you had shown me quickly as I would understand it then. Its working for you mate, I am not being critical of your decision to do it.

I cant understand it to see how I could use it - I am very space limited as well, thats a big problem, already lots of boxes - I initially was just looking a what mono block amp options I could fit in limited space as a boredom / research exercise more than anything - came across vincent hybrids. The hybrid seems another method of trying to do the same thing?

 

[Vladimir]

Actually technical minds have said valves in pre are superior to solid state if implemented well, as they are voltage masters, they do it very well, very forgiving tolerances unlike SS. A good pre should not have any 'tube character' to the sound, just great sound, period.

Their downside for typical dynamic speakers is low current delivery (coils generate EMF through current). However, not a problem for electrostatic speakers since they want more volts, not amperes. In case of dynamic speakers, you ideally want a hybrid amp, valve in pre, MOSFET in power, since FETs (field effect transistors) are the SS take on valves, extremely similar. BJT proponents will tell you, they like MOSFET as drivers or in preamps. For very inefficient current hungry speakers, BJT + FET/valves.

Even when valve amps fail, they succeed. Everyone likes valve harmonic distortion, it's bloody delicious. Musicians can't have enough of it. Thus, depending on application, no real downside of using valves. Maybe their life extension might be an inconvenience to some, but audiophiles LOVE to tinker and pamper their gear, therefore again, not a problem.

*All this as long as they don't burn your house to the ground.

 

[newlash09]

TAGA Harmony HTA-2000b. I cant make out much from the description on their website, but it sounds like a tube pre+ SS power amp, with a built-in dac. Could'nt find many reviews either. Hence my curiosity. Costs the equivalent of 1740 pounds where i live.

 

[ellisdj]

Actually technical minds have said valves in pre are superior to solid state if implemented well, as they are voltage masters, they do it very well, very forgiving tolerances unlike SS. A good pre should not have any 'tube character' to the sound, just great sound, period.

Their downside for typical dynamic speakers is low current delivery (coils generate EMF through current). However, not a problem for electrostatic speakers since they want more volts, not amperes. In case of dynamic speakers, you ideally want a hybrid amp, valve in pre, MOSFET in power, since FETs (field effect transistors) are the SS take on valves, extremely similar. BJT proponents will tell you, they like MOSFET as drivers or in preamps. For very inefficient current hungry speakers, BJT + FET/valves.

Even when valve amps fail, they succeed. Everyone likes valve harmonic distortion, it's bloody delicious. Musicians can't have enough of it. Thus, depending on application, no real downside of using valves. Maybe their life extension might be an inconvenience to some, but audiophiles LOVE to tinker and pamper their gear, therefore again, not a problem.

*All this as long as they don't burn your house to the ground.

Good write up thanks - what is BJT?

 

[Vladimir]

Actually technical minds have said valves in pre are superior to solid state if implemented well, as they are voltage masters, they do it very well, very forgiving tolerances unlike SS. A good pre should not have any 'tube character' to the sound, just great sound, period.

Their downside for typical dynamic speakers is low current delivery (coils generate EMF through current). However, not a problem for electrostatic speakers since they want more volts, not amperes. In case of dynamic speakers, you ideally want a hybrid amp, valve in pre, MOSFET in power, since FETs (field effect transistors) are the SS take on valves, extremely similar. BJT proponents will tell you, they like MOSFET as drivers or in preamps. For very inefficient current hungry speakers, BJT + FET/valves.

Even when valve amps fail, they succeed. Everyone likes valve harmonic distortion, it's bloody delicious. Musicians can't have enough of it. Thus, depending on application, no real downside of using valves. Maybe their life extension might be an inconvenience to some, but audiophiles LOVE to tinker and pamper their gear, therefore again, not a problem.

*All this as long as they don't burn your house to the ground.

Good write up thanks - what is BJT?

Bipolar Junction Transistors. It was a common practice if a manufacturer used FETs in their amps, to declare it in plain sight as a feature, otherwise it was assumed BJTs were used. It's the most common type of transistor used in SS amps.