Tube amps and speaker matching

[Swerd]

I know what you guys are saying. I just feel that it is worth pointing out the fact any well designed/built low power amps such as 50 WPC 8 ohms, 70 WPC 4 ohms, can do a good job on low impedance (yes even 2 ohms) and/or not too sensitive speakers if the room is small enough, sit close enough, and the user (like me) cannot stand spl much higher than 75 dB average.

For the benefit of cawleym (the OP) can you name some suitable examples of amps, including prices?

Remember, cawleym uses an integrated amp, the VTL IT85, plus an external amp, the VTL ST85. If he sold them, he would need a stand alone stereo pre-amp plus an external stereo amp, or an integrated stereo amplifier.

I would suggest an Outlaw RR2160 Stereo Receiver, which sells online for $849. It offers continuous average power of 110 watts per channel (20 Hz - 20kHz, <0.05% THD, both channels driven into 8 ohms) and 165 watts per channel (20 Hz - 20kHz,<0.05% THD, both channels driven into 4 ohms). It includes bass management with high- & low-pass filters with slopes of 12 dB/octave (2nd order), adjustable to 60, 80, 100 Hz, or bypass.

 

[TLS Guy]

Seems like a good little project, to modify the crossover.

It would be a project but not that easy. You would have to have the speakers shipped to you and then measure the Impedance, TL parameters and acoustic response before design could start. Then build the crossovers and install and more often then not modify according to measurements and listening. I would be prepared to do this, but not until we are moved into our new house and I have everything sorted and both workshops up and running properly.

 

[PENG]

It would be a project but not that easy. You would have to have the speakers shipped to you and then measure the Impedance, TL parameters and acoustic response before design could start. Then build the crossovers and install and more often then not modify according to measurements and listening. I would be prepared to do this, but not until we are moved into our new house and I have everything sorted and both workshops up and running properly.

I would love to do it too if I have tons of time lol.. Also, I would leave the crossover outside until I get better results. I thought it would be a piece of cake for Dennis, or you, who obvious have much more experience than someone like me. I do have books on my side.

 

[lovinthehd]

There are no jumpers in place as the Bi-amp set up has separate cables to each pair of posts (Instructions were to remove them in such a set up)

Anyway, lot to absorb here and perhaps I may have been sold a "bill of goods" by the tech. And I sure did spend some $$$.

I suppose people buy tube amps for a reason (other than nostolgia!) but maybe not.

Any way to make best use of the amps with a new speaker set up or something. Also, is there a guide to the physics of all these specs? I'd like to really understand the significance of crossover levels and impedance. A forum or book anyone can recommend ?

Well as far as forums, you're in a good one for learning. There's a large section of informational articles I'd recommend you check out for appropriate subject matter here on AH https://www.audioholics.com/av-research. You could then pick up various books on sound like Dr Toole's Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms, or perhaps one more about loudspeaker design like Vance Dickason's Loudspeaker Design Cookbook.

 

[TLS Guy]

I would love to do it too if I have tons of time lol.. Also, I would leave the crossover outside until I get better results. I thought it would be a piece of cake for Dennis, or you, who obvious have much more experience than someone like me. I do have books on my side.

You never know until you measure the drivers. Driver selection I always reckon is over half the battle. Not all drivers can work well together. If you randomly pick drivers out of the air, more often than not you will find there is no decent passive solution.

 

[cawleym]

WOW Appreciate all the feedback (even though I'm struggling to grasp it all) Though it is now clear the set up is not working for various reasons) Perhaps I scrap the speakers to my secondary system in the basement (which has a SS NAD integrated amp) and sell the VTLs. , or get a pair of 8 ohm speakers and try to live with the VTL's. Not sure yet.

PS I did spend a lot of $$ on tube amp because "they have a warmer sound" says the salesman.

So why do people get tube amps if they are so finicky and hard to match with components?

 

[TLS Guy]

WOW Appreciate all the feedback (even though I'm struggling to grasp it all) Though it is now clear the set up is not working for various reasons) Perhaps I scrap the speakers to my secondary system in the basement (which has a SS NAD integrated amp) and sell the VTLs. , or get a pair of 8 ohm speakers and try to live with the VTL's. Not sure yet.

PS I did spend a lot of $$ on tube amp because "they have a warmer sound" says the salesman.

So why do people get tube amps if they are so finicky and hard to match with components?

As I said the salesman was an idiot. Tube amps are less then ideal for most modern speaker systems. Only a few of the very best come even close to matching solid state amps under some circumstances. Most are actually worse than even the cheapest solid state amps. No tube amp can match the best solid state amps.

The biggest Achilles heel of all is that they are a high impedance voltage source and not a low impedance current source. So this makes for your big issue, that because of the high output impedance the frequency response wants to follow the impedance curve, which is never flat. However sometimes you get lucky. If there is a dip in impedance in the 2 to 3k range and the speaker has a peak there, which far too many speakers do, then the speaker will be tamed on a tuba amp and people will say the tube amp is smoother and warmer. Conversely if the speaker has a rising impedance at the very top end, which is common, then the audiophools proclaim the speaker has more "air". They are just too ignorant to understand the how and the why.

I can tell you one thing that if there were not compromised speakers abounding, to give a chance of getting lucky with correction by a tube amp, there would be no misguided tube amp craze.

Lastly solid state amps are much more reliable and less trouble than tube amps.

If it were me I would sell the VTL amps. Then get some speakers you are really happy with. I can tell you that the answer to a happy audio existence is good accurate speakers, good accurate speakers and more good accurate speakers. The real trouble is that they are far and few between.

 

[ryanosaur]

If it where me I would sell the VTL amps. Then get some speakers you are really happy with. I can tell you that the answer to a happy audio existence is good accurate speakers, good accurate speakers and more good accurate speakers.

THIS! +1000
My introduction to such has been great and I don't think I could ever go back to the majority of OEM/mass market gear.

 

[PENG]

For the benefit of cawleym (the OP) can you name some suitable examples of amps, including prices?

Remember, cawleym uses an integrated amp, the VTL IT85, plus an external amp, the VTL ST85. If he sold them, he would need a stand alone stereo pre-amp plus an external stereo amp, or an integrated stereo amplifier.

I would suggest an Outlaw RR2160 Stereo Receiver, which sells online for $849. It offers continuous average power of 110 watts per channel (20 Hz - 20kHz, <0.05% THD, both channels driven into 8 ohms) and 165 watts per channel (20 Hz - 20kHz,<0.05% THD, both channels driven into 4 ohms). It includes bass management with high- & low-pass filters with slopes of 12 dB/octave (2nd order),adjustable to 60, 80, 100 Hz, or bypass.

We need to know his seating distance, and desired spl at the minimum. Without the info, we can only make our own assumption. Since his two VTL amps can't do much more than 50 W, likely much less into 4, 2 ohms, even if we ignore the poor output impedance, and he is not complaining about not loud enough, just no bass, so I do suspect he may do fine with the RR2160, or any of NAD's class AB integrated amps from the C326BEE and up, basically any truly high current (relatively speaking) amps will do.

 

[cawleym]

MY room is 15 by 33 feet. Speakers are along the long wall. Seating is 10 feet from speakers which are at 4 foot height. 8.5 foot ceiling. Lots of area rugs and furniture so it not a hard room at all.

Volume is fine at about half way up on the knob, issue is the lack of bass as far as sound is concerned though I gather I have other issues from the thread here. especially the low impedance and inferior crossover.

I have an old NAD that I love. May hook that up to the speakers as a secondary unit while I rebuild the primary system

Thanks to all!

 

[PENG]

MY room is 15 by 33 feet. Speakers are along the long wall. Seating is 10 feet from speakers which are at 4 foot height. 8.5 foot ceiling. Lots of area rugs and furniture so it not a hard room at all.

Volume is fine at about half way up on the knob, issue is the lack of bass as far as sound is concerned though I gather I have other issues from the thread here. especially the low impedance and inferior crossover.

I have an old NAD that I love. May hook that up to the speakers as a secondary unit while I rebuild the primary system

Thanks to all!

Vol position won't tell us much because it depends..
Since lack of bass is your only issue now, if your old NAD is rated at least 50 watt into 8 ohms, it would likely do a better job than the VTLs.