Tube amp Questions

Hi everyone

The questions are… What tube amp setup would you reccommend to incorporate into this configuration?

What do you look for in a good Tube Amp?

I like the HK 990. However I would like to move to the Tube end of things and experience that sound.

I know I will need to audition a few to see what sound I prefer. I just figured with all the knowlegde and experience on this forum a couple of you could suggest some give a listen to.

Looking at around a $3000 limit.

My current system is…

Harman Kardon HK990 intergrated

Revel F52 speakers


VPI Aries Scout with an Ortofon 2m Bronze mm cart

Herron VTPH 1mm phono preamp

Oppo 105D 

Belden BJC LC-1 interconnects

12 gauge, 87 strand, oxygen free copper speaker cables

The SVS Sub and VPI are nicely isolated. 

I'm going to upgrade the sub to a SVS SB13 Ultra. 

Thanks for taking some time out of your day to respond.



I like adjustability and built quality of vintage tube amps:
Sansui 2000, Fisher 400, Marantz Model 8, Scott 292 or other Scott tube models.
VU meters of Marantz Model 8 are eye magnets and the whole faceplate as well.
Marantz Model 8 may cost you far more, but it will never loose a dime if you want to sell it and it sounds very strong with some solid state bass. Truly unique tube unit that's worth attention.

i found your speaker specs here:

The F52 is a 6.5 Ohms nominal impedance speaker & they seem to have determined its sensitivity by inputing 2.83V. That input power is 1.23W instead of 1W. 10*log10(1.23) is 0.9dB. so, i would subtract 0.9dB from the 87.5dB sensitivity thereby making the F52 a 86.6dB/1W/1m speaker. That's not a very efficient speaker. At your listening position 10ft away (assuming you are at 10' away) your SPL would be in the 76.6dB with 1W output from an amplifier. 
I believe that you would need a large output tube amplifier to make the F52 yield its best. 
At 1st i was going to suggest a Rogue Cronus Magnum 2 integrated by after doing the math i don't think it will be sufficient. Sure you'll get music out of the F52 but it won't make the F52 sound its best. Maybe the Rogue Pharaoh tube hybrid at 185W/ch might cut it..... 

+2 Rogue Audio! Check out their integrated amps!
Or get different speakers :)
Specs I saw said 87.5db sensitivity.  Not great, but not too bad.  I would check out PrimaLuna offerings for great price:performance.
I like my speakers so they aren't going anywhere anytime soon. 

With the right amount of power they sound great. So I guess that is an important component of any Amp or Intergrated that would be on my list.
The Hk990 is 150w/ch into 8 Ohms. 

I like the hybrid design of the Rogue Pharaoh and will read more about it and see if I can find a dealer close by.  I'll also look into the PrimaLuna's.

Thanks for all the info and quick replies.

101 posts
09-09-2016 1:05am
Specs I saw said 87.5db sensitivity.
theothergreg, you might want to read my post (above/before yours) in this thread. I believe the stated spec of 87.5dB is not totally correct.... 
The Revel F52 is not a speaker that should be used with a tube power amp. In addition to the low sensitivity, reviews have cited issues with impedance and phase angle and said it is somewhat difficult to drive. Since you want tubes in the system, the hybrid integrated with tube preamp and ss power amp is the best choice.

Thanks tis49.

Are there other options besides going Rogue? 
bombaywalla1,954 posts09-09-2016 5:14am
101 posts
09-09-2016 1:05am
Specs I saw said 87.5db sensitivity.
theothergreg, you might want to read my post (above/before yours) in this thread. I believe the stated spec of 87.5dB is not totally correct....

@bombaywalla:  Noted, thanks.
Hi Mark...I have F52`s and I had a Rogue ST 90 with KT 120`s and it sounded very nice !
 I decided to sell the Rogue and look for a tube amp with more power.
Meanwhile, as a stop gap I bought a Class D Audio SDS 470C which has 300 watts @ 8 ohm, 600 watts @ 4 ohm.
Now I`m having a hard time justifying a move away from the 470C.
The width is way wide, has nice depth and plenty of power (never pushed it hard though)
I just added some tubes into the mix with a Herron phono stage and that may be the answer/solution to some of the differences I heard between the two amps.

I don`t agree that the F52`s should not be used with tube amps.
I may even go back to a Rogue via an Atlas Magnum or ST100. I`m sure the M180`s would be REALLY nice !!!
 A Quicksilver V4 is an interesting option too.
Anyway the SDS 470 is only $700 or so and IMO priced way too low for how good it sounds.

I have Revel F52s and have tried them with PrimaLuna Dialogue Premium HP Integrated at about 75 watt/channel. Sounds good but I agree with the assessment that the 52s do better with real power. Now have the PrimaLuna connected to Revel F206s and felt they were a little flat until I swapped in the KT150 tubes which give it about 100 watts/. If I were trying to get the most from an F52/tube combo, I would use a tube preamp and a SS amp. In fact I am waiting for my tube ModWright Oppo 105 to front a Krell Foundation/Krell TAS to my F52s. A lot of people think a hybrid setup gives the best of both worlds.
As I often note, Jolida makes some of the "best bang for the buck" tube stuff around. These guys should reward me for all the free promotion I give them but do they? NO…anyway, their new stuff is likely even better than my older 502p and at least worth a look. Powerful and reliable tube rollers fun spot. Note I found a great SS preamp to use with the 502, and that's how I roll…I'm of the "clean signal into grease pit" school of thought for my stereo rig. 
If wanting an integrated look into the Vincent audio 237.  Retails at ~$2500. 150wpc 8 ohms, 300 4 ohms. Might check out audio advisor for this unit.
Somewhere else there's recent talk of Vincent stuff (my preamp is a re-badged Vincent by Kavent), and a good friend of mine has a 236. Note that the 236 (and I assume the 237) is HUGE…seriously a great value if only a "size for the bucks" thing, although it does sound great.
So, I’m leaing towards the Rogue Pharaoh with the hybrid tube /ss design.

However, are there more powerful options out there in the Hybrid realm of amps… say 250 to 300 watts/channel into 8 ohms?
Check out Audio By Van Alstine, one of their Fet Valve Hybrid Amplifiers. My speakers' rated sensitivity are similar to yours and I had an earlier edition Fet Valve and liked it very much. A little tube flavor with lots of power. Very well built, sounds great, lots of power, reasonably priced, built in USA (if that matters to you), and terrific customer support. I would still own it today had I not pursued an all-tube power amplifier.

So The Van Alstine 600-R is an Amp not an Intergrated.

If I went that way could I use my HK990 as a Pre amp?  And how would I hook that up? 

Would that be going the opposite way using a solid state pre amp with a tube amp? As I understand it's best to use a tube pre amp with a Solid State Amp…. right?

Or could I use my Oppo 105D as a preamp? I have read where that might not be the best thing to do. 

To clarify my previous question… Are there more Powerful Hybrid Integrated options to the Rogue Pharaoh Hybrid Integrated out there? 
Correct, the 600-R is not an integrated amp, sorry, my bad.
Many integrated amps have pre amp outputs (line level) to connect to power amps - not sure if yours does but would be surprised if it does not.
If it does you could connect your current integrated pre amp outputs to a separate power amp (solid state, hybrid, or tube). That is what I did when I purchased my AVA hybrid Fet Valve power amp - connected my existing pre amp outputs to it.
Some people prefer solid state pre amps with hybrid or tube power amps. There is no "best" or right way as far as that goes - that is up to your brain/ears. Assuming the gear matches up properly (input/output impedances).
Last I knew AVA would allow a trial period so you could try it out to see if you like it. You would be responsible for the cost of return shipping only if you disliked the sound.
I "progressed" from my hybrid integrated; to using it as a pre amp with AVA Fet Valve hybrid amp; to replacing the integrated with an all-tube pre amp; and finally replacing the Fet Valve power amp with an all-tube power amp. Each step along the way I discovered I wanted more and more of what proper tubes can do for the sound. So much that I ended up with all tube gear.
However you go, good luck in your pursuit of audio perfection!

Went away from the tubes and bought a Coda CSIB integrated. 

It just arrived but due to my work schedule I won't be able to get it into my system until after Christmas.

Thanks to all of you who shared your knowledge and took time out of your life's to help guide me.

Happy Holidays!