Tube Amp with tone controls for Heresy IV's

"Heresy IVs, a big passive radiator on the back"
That's the Forte IV.  The Heresy IV is ported on back. 

@jab
All tube amps have tone controls, they are called tubes. Different brands have their own sound, from bright to dark sounding.

Do you change your tubes out every time on sub-optimal recorded music or restrict listening only to the best recordings?

@oldhvymec
I run Cary V12R at 100 wpc and EL34. They work perfect for me 60 hz and up. BUT I use them at 300hz and up.. Just a perfect valve for mids and highs...BASS not so much.. 60 hz and up will work though..

My former V12R with had gobbs of bass, way more than I needed, even comparing to my Cary SA-200-2. solid state amp; 92.5 db speakers. It’s all speaker dependent too. I loved the sound of my EL34s in the V12R.


Keep in mind, the OP has Hersey IVs, a big passive radiator on the back, super-sensitive at 99DB efficiency. Friends of mine run IVs with 10watt Triode amps, 6L6, KT77, KT88s, plenty of bass in the right room setting.

Holger’s EL34 40W/ch (Erhart-Audio) Basie amp is plenty for Hersey IVs. However I agree KT88s and higher do offer more bass drive in the right amp.

That good to know, and pretty reasonable too.. I just looked at that.. El34s. Not for bass duty, sorry... that would be a no go for me. 6L6, KT88, or 90s, IF I had to do bass duty too..

I run Cary V12R at 100 wpc and EL34. They work perfect for me 60 hz and up. BUT I use them at 300hz and up.. Just a perfect valve for mids and highs...BASS not so much.. 60 hz and up will work though..

Regards

"Basie" by Erhard-Audio $2495

https://www.erhard-audio.com/Basie.html

Tone controls with tone defeat too. 
A buddy has the same unit in preamp form with tone controls. He's used this setup with Klipsch Hersey III and his new Klipsch Hersey IVs.  Even with his tube R2R Ladder DAC, says the tone controls can be necessary when listening to less favorable recordings on streaming. -2 on treble some times to reduce digital grain and make it more listenable.  

Not just finding them but for 3K or <  that sounds good too. I don't know of any integrated valve amps.. Sansui maybe, if you can find a good one to rebuild..

I'd say it's going to be an older unit, if at all, for me anyways.
New, not gonna happen, used if it's older an probably rebuilt, for my taste.

Separates, no problem.. ANY older tube Mac pre any older Mac valve amp.. They will work.. Actually made for Klipsch, JBL, Jensen and Altec.
BUT you gotta have GOOD tone control.. Not just tone control.. I like Macs, loudness, bass contour AND tone control.. all of those features (C20) make a Mac very versatile.. Takes a lot of the "tube rolling" crap out of the mix too..

Regards

leben cs 300, cs600 has 3 steps bass boost control

just use a schiit loki coupled with any tube amp you want

easier and more straightforward than finding the unicorn modern day tube amp w tone controls... there is a reason you are having trouble finding them...