305 WPC Pure Tube Bliss

[Southern]

I have been experimenting with my 270 WPC Pioneer SX-1980 and my Dynaco ST70. First I bi-amp them through the Pioneer with a home-made (line level) tube pre-amp. They sounded great seperately but when I bi-amp them there seemed to be a hole in the midrange. Then I connected my Dynaco PAS-2 pre-amp instead of my home-made pre-amp.

At first I just had the Pioneer connected and when I pipped in music I thought that my Dynaco ST70 had grown balls. It was amazing how much my Pioneer had sounded like the Dynaco amp, very articulate warm sounding but with the chest thumping bass.

Then I bi-amped the Dynaco amp with my Pioneer (Pioneer 270 wpc feeding the lows, Dynaco 35 wpc feeding the mid/highs) which is 305 wpc of pure tube bliss.

My speakers are the orginal Forte 1's that have been re-capped and modified for bi-amping. Here is the link with pictures: http://www.audiokarma.org/forums/showthread.php?t=94027

I have been talking about bi-amping my Pioneer with my Dynaco for years and I have finally done it, thanks to SWL for encourging me and after hearing his RF-7's bi-amped. My next step is to drag my RF-7s down stairs and hear how they sound with my 2-channel setup. I previously had my Dynaco amp and pre-amp playing thorugh the RF-7's and I was astonished on how silky smooth the mid/high end was, it just didn't have any chest thumping bass.

[runninshine]

Atta boy! Now tell us what you're listing to.

[Southern]

At the moment I am listening to Nils Lofgren Acoustic Live CD. When the wife is not home I crank up

up some Godsmack.

[SWL]

That's great to hear, Ray. Now I gotta get over there and hear it soon! I'll help you lug the 7's.

Similar to my experience with my KLF-30's. I'm a happy camper with tubes on the highs, high current solid state amp on the lows and my Jolida JD100a tube cd player makes for an excellent combination.

Congrats. [Y]

[Southern]

Bring your Jolida over with some of your music and will compair the Forte's with the RF7's.[]

[CapZark]

Funny, how I just came across this thread. I have a Pioneer SX-1980 and a pair of La Scala and a pair of Heresy hooked up to it along with a Velodyne sub. Tonight I am listening to an old Chicago album and thinking to myself, the only way this could possibly sound any better is to buy a tube amp. But I don't know anything about tube amps and then I came across your post. What tube amp should I be looking for? What is bi-amping? This all sounds very intriguing to me. I hope you can give me a few pointers in my latest quest to improve my sound - if that is even possible??

[Southern]

Bi-amping is having one amp powering the woofers and another amp powering the mid/highs.

You would need to modify your crossovers to bi-amp your speakers since you have only one pair of speaker

connections. Others would argue that I have a "fools" bi-amped system since I am using the passive crossovers.

I have discovered that you can get a tube sound with your Pioneer by connecting a tube pre-amp

to it. There are pre-amp out/power amp in jacks in the back that allow you to do this.

[russ69]

Not to bust your chops but you have 35 watts of pure tube bliss not 305 watts. If I hook my two Velodynes up to my 25 watt tube amps, I'll have 1275 watts per channel! 300 watts of tube power is going to cost a bit of money and a lot more air conditioning. Rock on.

[artarama]

Not to bust your chops but you have 35 watts of pure tube bliss not 305 watts. If I hook my two Velodynes up to my 25 watt tube amps, I'll have 1275 watts per channel! 300 watts of tube power is going to cost a bit of money and a lot more air conditioning. Rock on.

Russ, Thanks for keeping it real.

The thread reads correctly, but this is how manufactures specs start to lose their meaning.

[SWL]

Others would argue that I have a "fools" bi-amped system since I am using the passive crossovers.

It's "passive bi-amping".

[Southern]

You are technically correct but I am still amazed on how the tube pre-amp makes my solid state amp sound very close to my tube amp. I encourage anyone with a "old school" receiver with pre-out/power-in jacks to hook-up a tube pre-amp and give it a listen.

[SET12]

You are technically correct but I am still amazed on how the tube pre-amp makes my solid state amp sound very close to my tube amp. I encourage anyone with a "old school" receiver with pre-out/power-in jacks to hook-up a tube pre-amp and give it a listen.

Yes using a tube pre is a very nice combination! But...

In referance to using a tube power amp biamping.

I hate to burst the bubble but I'm sorry to say you're risking damaging the tube amplifier.

SS amplifiers of course can run in no load situations all day long.

One should never run a tube amp without a load.

Passive crossovers of today are typically not set up to do this.

The reason there is no load is that the network delivers power to the driver only at the appropriate frequencies and blocks power at the non appropriate ones. Creating a large nearly infinite load, this is the unloading effect.

Unloading a tube amplifier while sending a signal to it produces very
dangerous levels of high voltage across its transformers primary
windings. This voltage can arc over the transformers winding insulation
causing internal shorting, it can also cause output tubes to arc over as
well.

Basically what ever is on the tube amps secondary for a load is reflected back to the primary, the transformer for instance with a 16 ohm load on the 8 ohm tap will reflect twice the primaries impedance which would be an 8.6K load. much worse would be putting a 16 ohm load on a 4 ohm tap creating a 17.2 k primary and of course nothing represents infinite secondary loading!

You should also know you can do damage with out seeing or hearing as
well, and if it hasn't happened yet it may very well happen in the near
future depending on signal levels in the amp.

If you're going to do this at least put a 16 ohm loading resistor across the tube amp, You can buy 8 ohm 20 watt non loading inductive resistors from radio shack use two in series for 16 ohms.

SET12

[Southern]

If you're going to do this at least put a 16 ohm loading resistor across the tube amp, You can buy 8 ohm 20 watt non loading inductive resistors from radio shack use two in series for 16 ohms.

SET12

I am using the 8 ohm tap from my Dyanco to the mid/highs of my Forte crossover. If I am understanding you correct you recommend putting a 16 ohm
resisitor in parallel with my tube amp (at the output)?

I thought about the fact that I am putting the full frequency spectrum of my amps to each of the passive crossovers and considered using an active filter up front to only amplify the lows or mids/highs to the passive crossovers. Any thoughts?

[SET12]

If you're going to do this at least put a 16 ohm loading resistor across the tube amp, You can buy 8 ohm 20 watt non loading inductive resistors from radio shack use two in series for 16 ohms.

SET12

I am using the 8 ohm tap from my Dyanco to the mid/highs of my Forte crossover. If I am understanding you correct you recommend putting a 16 ohm
resisitor in parallel with my tube amp (at the output)?

I thought about the fact that I am putting the full frequency spectrum of my amps to each of the passive crossovers and considered using an active filter up front to only amplify the lows or mids/highs to the passive crossovers. Any thoughts?

Yes thats correct use a 16 ohm load on the 8 ohm tap of your amps the other choice is the active filter, But it's not my first choice, others maybe.

A better way would be to use a filter or filters internally in your amp to roll off the lows by changing coupling caps. I saw this being done in a system owned by Arthur Loesch and I thought wow that's pretty cool, as it eliminated gainstages used in an active network.

I have not done it myself but if I were to, this is how I would do it. As there is to much is loss in transparency for my tastes along with other things. I have more than enough gain from my power amps to use them direct with my CDP. Every preamp but one has been a compromise for me, and that preamp was $5000. I could attempt to build one but it would be very difficult to match it.

But consider what this guy has done and where he was with tri-amping.

http://www.audioasylum.com/forums/hug/messages/14/147282.html

I couldn't agree with him more! He found great satisfaction in going with some of the worlds largest Inductors as I have and I'm sure his caps and resistors he's using are rated very high subjectively as well as mine in my own networks.

Bottom line is that he found some of the most subjective satisfaction in more than 10yrs of listening to his new passive crossover networks. Allowing him to use his best amplifier full range. And achieveing as good or better subjective satisfaction.

I wouldn't trade my North Creek low frequency 8AWG inductors for any sub, simply because the Inductor covers more range than any sub. And the sheer grip of these inductors is tractor like or jackhammer like in the lows as SWL who has heard them has said.Also I wouldn't give my 8AWG tweeter inductors up either, there is just something about them that give an effortless presentation, along with a sound stage that is nearly double the size of the stock Fortes.

I'm having the most fun and satisfaction I have ever had in 35yrs of audio and that includes seeing facial expressions of others when they hear the results as well, which is priceless.

Been down many roads, no doubt everyone has to travel theirs, but lately I have been just flying.

SET12

[SWL]

One should never run a tube amp without a load.

Dan,

I'm doing something similar. A 20 wpc HH Scott 222c powering the mids-highs on FOUR KLF-30's. It has 4,8 and 16 ohms taps. What do you reccomend? Does powering four speakers rather than only two take up the slack?

[artto]

At first I just had the Pioneer connected and when I pipped in music I thought that my Dynaco ST70 had grown balls. It was amazing how much my Pioneer had sounded like the Dynaco amp, very articulate warm sounding but with the chest thumping bass.

Then I bi-amped the Dynaco amp with my Pioneer (Pioneer 270 wpc feeding the lows, Dynaco 35 wpc feeding the mid/highs) which is 305 wpc of pure tube bliss.

ummm.....270wpc solid state poison, oops, I mean power, + 35wpc tube power does not equal 305wpc of pure tube bliss. For that I'm afraid you'll need something like this:

http://www.mcintoshlabs.com/products/1112.asp

or this:

http://www.audioresearch.com/reference210.htm

I'm continually surprised at how many folks equate 1970/80's consumer grade run-of-the-mill solid state amplifiers, and especially recievers as being really good stuff simply because it fits the definition of "vintage". Those were some of the worse sounding audio components ever made.

Anyone who thinks that a Pioneer SX series reciever is "warm and articulate", especially in direct comparison with highly regarded tube amp like the Dynaco...............................................well, I'll just be nice and let you use your imagination.

It all reminds me of long, long ago, when one of my best friends traded in his 30 watt Fisher tube integrated for a high powered Pioneer SX reciever. Sure looked pretty. Wish I could say the same for the sound. In fact, later in life the memory of that very instance is what turned me back to valves.

You're in Carol Stream ~ not too far from me ~ you are hereby invited to hear what tube bliss really sounds like. PM me if you like.

[Southern]

Anyone who thinks that a Pioneer SX series reciever is "warm and articulate", especially in direct comparison with highly regarded tube amp like the Dynaco...............................................well, I'll just be nice and let you use your imagination.

Talk about judging a book by it's cover Artto. I acknowlege your invite and invite you to hear my imagination.

PM sent

[SWL]

especially recievers as being really good stuff simply because it fits the definition of "vintage". Those were some of the worse sounding audio components ever made.

That's a very arrogant statement. I agree with most 80's stuff sounding very poor but the 70's stuff just happens to have the "grungy" sound that a lot of us like. I believe that certain types of gear can lend itself to certain types of music. Clean, detailed, transparent sound doesn't always jive with classic rock, hard rock or heavy metal. Sometimes distortion is good as long as everything in the system is working together.

"Tube bliss" I would think describes listening to Diana Krall on an all tube system. Metallica......I doubt it.

[Southern]

One should never run a tube amp without a load.

Dan,

I'm doing something similar. A 20 wpc HH Scott 222c powering the mids-highs on FOUR KLF-30's. It has 4,8 and 16 ohms taps. What do you reccomend? Does powering four speakers rather than only two take up the slack?

Scott, I did what SET12 suggested and noticed better separation between the bass and the mid/highs, thanks SET12.

I ended up using what I found in my basement, used two 33 ohm resistors (2W wire wound) wired in parallel.

[russ69]

I'm continually surprised at how many folks equate 1970/80's consumer grade run-of-the-mill solid state amplifiers, and especially recievers as being really good stuff simply because it fits the definition of "vintage". Those were some of the worse sounding audio components ever made.

Anyone who thinks that a Pioneer SX series reciever is "warm and articulate", especially in direct comparison with highly regarded tube amp like the Dynaco...............................................well, I'll just be nice and let you use your imagination.

Right on Artto, and I had a "vintage SX receiver" back when it wasn't vintage. That was the last receiver I ever owned. I haven't gone backwards since.

Thanx, Russ