Amplifier pairing for Altec Flamencos

I am considering adding a new amplifier to try out in my current system and could use some advice on choices to consider that would be an upgrade and complimentary to  my setup.  I have a pair of Altec Flamencos modified with the Werner Jagusch crossovers and play them with my Don Sachs preamp and a Tubes 4 HiFi  ST 120 push pull tube amp. Listening source is Bluesound node 2i with Schiit Modi Multibit Dac.   I have also been utilizing an SVS SB 1000 with them. I am not positive that my current amp is affording the old Altecs the level of dynamics and resolution that they are capable of achieving. My normal avg listening level is 75db with peaks hitting low 90s db.  Though, on occasion, I will go to 11.   What amp will resolve this question? My budget for the amp new or used is up to $3500.  


Thanks for your input.  Do you think your new class D mono blocks would be a good fit for the 16 ohm Altecs? Or should I stick with a tube amplifier for this speaker? I think my current tube amp falls within the parameters you outlined, but it is the only tube amp i have ever owned so i have no reference for judging its performance.  

@jplunkettj My speakers are also 16 Ohms and they work fine with the class Ds. A good tube amp will work fine too.

I essentially have the same speaker, which is the Altec 846A. I also use the Werner Jagusch (Mass Mutter on eBay...?) Crossover. The Altec’s with the Werner XO have a very high performance ceiling. I use a Shindo Parallel SET 300B, which is 18 watts. I would like to hear a 40-50 watt PP tube amp, but I can’t say my amp is lacking on power. It may not have the grunt of a KT 88, but there’s always a trade off. There are so many interesting choices that you could consider. I would start with the type of sound you are looking for. I know this may cause a mini uproar, but the type of music you listen to should come in to play. If you’re a newbie jazz guy that has always listened to rock like Steely Dan, The Police, CSN, and singer songwriter stuff, I love the 300B. Perhaps the 211/845 tube should also be considered. I may throw on Zeppellin or Sabbath on every 5th listening session, and for that I would love to have a KT 77, 88, or even an 845 amp in my arsenal. But I still enjoy the harder rock on my Shindo. As for amps suggestions, perhaps the above mentioned OTL is a nice. option. For Push Pull, maybe a used Audio Hungary or Lab 12. A used Shindo Montille may also come in within your budget.

I have experience with Aletec 604E that has similar sensitivity to Altec 846A.

In the mid size rooms that I had 200-300 sq feet, 300B SET has enough power. I used McIntosh MC30 monoblocks (30+ watt), Marantz 8B in triode mode (20 watt), and 300B SET (6-7 watt). I also heard 2a3 Boothed monoblocks with my speakers and they were good enough in terms of power. 

The 30 watt McIntosh MC30 sounded great with my Spendor 2/3 speakers but with super sensitive Altecs it sounded rough and not as natural and refined as a 300B amplifier. 
What is really important is that for a 300B amplifier it has to have a powerful driver tube like 6f6, 6v6 but not popular but weak 6sn7.
The strong power supply with a big and good quality capacitor.
If your room is not huge, I suggest you try Coincident Frankenstein 300b monoblocks or Aric Audio Super 300B SET. Both these amplifiers have powerful driver tubes, interstage transformers and good power supply.

Here are my two cents about Werner Jagusch crossovers.
I used my Altec 604E with the original n1500 corosvers. Then I bought Werner Jagusch crossovers. First impression was very good, but then I realised that the sound is too coloured. I bought a measuring microphone, Minidsp umik-1 and measured speakers. I saw the issues of this crossovers:
1. No frequency correction of the HF compression driver caused significant frequency drop above 4KHz.
2. First order HF compression driver crossover led to not suppressed inverted phase output of derived below crossover frequency that caused significant frequency response dip.
I decided to build a crossover based on n1500 schematics but with modern good quality parts. I got a much flatter frequency response and more importantly a much better sound.

@fjn04  Thanks for recounting your experiences and impressions and most importantly suggestions on amps to look for.

@alexberger Thank you for your very detailed account of your experience and suggestions.  This is invaluable information! I still have the original crossovers mounted on the original backs.  I may have to  reinstall them to see how they compare to the Werner Jagusch. Who did you use/ who would you suggest that I contact to build  upgraded crossovers for Flamencos? Great Plains Audio?