Best 300b single-ended Tube amp. for the $

What price range are you talking about?

Saffy,

Decide on high efficiency speakers first because they will be the biggest determining factor in a low-power system depending on space, musical preferences, and replay volume. A better understanding of your preferences/needs would really help us with suggestions.

If you are into Mahler at realistic volumes with the least amount of distortion and greatest dynamics, a 100+dB multi-way compression horn system would probably be best.

Intimate acoustic, jazz trio, quartet, vocals etc...that's where full range single-driver systems excel.

In between, multi-way compression/dynamic hymbris and SET-friendly multi-way dynamic speakers like Silverline. etc.

The musical presentation is so incredibly different between those 4 major categories, and even within them, that you really need to arrange to hear other people's high-eff setups before making the jump.

As for amps, depending on the speakers you choose, you may not have to limited to 300B amps. There several other fantastic output tubes that equal, or even exceed, 300B's in many ways.

You've already heard and marveled at an Art Audio amp. The owner, Joe Fratus, considers their PX-25(which I own) to be their finest. It has 6wpc output, but out drives many 300B or other higher powered SET's. These sell here for $2,500-3,200 used regularly and hold their value at that price. Also consider their 845 based Carissa.

Welborne Labs 300B DRD or Terraplane monoblocks are amazing. DIY HiFi Supply's Lady Day+ monoblocks are great and have a large following.

The hard part is finding new high efficiency speakers in his $2,000-3,000 range that will properly fill a large room.

Used though, opens a pretty large selection:
Klipschorn/La Scala types
Silverline Sonata/Sonatina
Von Schweikerts
Living Voice Auditoriums
Classic Altec Voice of the Theatre style Valencia's

"My monitors are 89db @ 7ohms,though if I added a powered sub wouldn't that compensate a little power distribution-wise?"

Not unless you included some type of "high-pass" filter before the amp to block low frequencies from reaching it. Even then, it may not work depending on the impedance curve of your speakers.

Bottom line, your speakers probably were not designed to be used with low-powered SET amps, so don't waste your energy trying doing so. That would be an attempt to use the wrong tool for a specific job.

The goal is not have a system that simply works, but to have one that works to the best of it's abilities. Your speakers will not provide that with lower-powered SETs.

On the other hand, Art Audio's 16wpc Carissa (845 tube), or even better, 20/32wpc Jota (depending on output tube) probably will drive your speakers fairly well. But, they do not have the same "magic" of the lower powered offerings. Although, they do have their own benefits in the area of lushness and slam, respectively. Either of these amps could potentially make a fantastic match with your current speakers.

Please heed the advice people are trying giving you here, low-power SET systems requirement far more planning and understanding than normal high power setups. There are no shortcuts, there are no free lunches.

Good choice Saffy,

The PX-25 is one of the finest amps I have ever heard. It has a musical quality that is entirely unique, one reviewer coined the phrase "as if instruments were lit from within". I agree.

The PX is 6wpc, but has current capabilities beyond the normal 6-10wpc SET amp. I suggest speakers of >95dB to really let the amp shine.

I'm partial to single-driver, or more accurately, wide-range driver speakers. They usually feature a 1st order, or no, crossover at all, which along with the single point of origin for the majority of the frequency range leads to a greater time and phase coherence than multi-driver speakers with higher order crossovers.

By "musical coherence" I mean that is as if all sound flows from a single musical tapestry. Not one dimensional, but a beautifully woven soundscape of depth and nuance. Done properly, it is awe inspiring and there is nothing like it.

But, that isn't the only, or even best, approach. Like everything in audio, which is best for you is a personal choice and may not be the same for anyone else.

Welborne Labs, which also makes fantastic SET amps, has a great page listing speakers that mate well with SET amps. They also have a short primer on proper speaker matching.

The best advice I could offer for anyone interested in high-eff speakers would be to check here, Audio Asylum's High Efficiency Speaker forum, and on the Fullrange Driver Forum for a horn or high-eff listeners group in your city. At the very least, there might a few owners in your area. Ask if you can check out their systems. The more you hear the better.

Take your time before jumping in, high-eff systems are much harder to get right than most people would think. And enjoy the learning process.

Hi Saffy,

In response to your questions:

1. Both the Druid and Abbys are great speakers, especially Abbys for the money. I think the two do really well in small to medium sized rooms. Both benefit greatly from a subwoofer. Although, the Druids deliver surprisingly deep bass for a cabinet that is only 6.5" deep, really perplexing how they do that.

Zu seems to be one of those products that evoke strong responses, both pro and con. Some of those who dislike them have actually heard them, a lot have not. You have to decide for yourself and Zu's 30-day money back guarantee assures just that. Not many other manufacturers are that generous.

Oddly, we tried my PX-25 with Abbys but actually preferred the $800 Almarro A205A with it. The A205A is a single-ended pentode (SEP) amp that has sonic performance leagues beyond it's price. Paired with the Abby, it is sublime when you take cost into consideration. A few cheap upgrades to the Almarro make it a real giant killer.

As for other speaker options, please let us know your room dimensions, average listening level, and how far you sit away?

2. Low-power, high sensitivity, systems are far more revealing(IMO) to component and cables changes than high powered systems. Noise is also a big problem. For example, when I had 90dB speakers, my system was dead quiet. But, when i switched to 97dB speakers and <8wpc SETs, it became glaringly clear that I had a loud 60Hz hum problem in my household electrical system. The hum was clearly audible at my listening position 14+ feet away. I had to re-ground my breaker panel and then use balanced isolation transformers before my audio system before I could get it truly quiet. Never knew the noise was there with 90dB speakers.

I've also found that cable changes are far more pronounced with the high-eff system.

3. If you only have one source, then no need for a linestage. Whether the PX-25 passive will work well for you is really dependent on the output of your cd/turntable/tuner, etc. The PX has an input sensitivity of 0.7V, so anything with 1.5V output will do really well as long as you keep interconnects short. I probably wouldn't use anything that has under 1.2V output, a little headroom is always good so that the sources output stage isn't stressed at all - they distort badly when pushed hard.

Nice digital front end, Saffy. I have the Museatex/Meitner Bitstream dac(3V/300ohm output) which had full signal & power supply upgrades by John Wright of Museatex in Nov 2005. Definitely works extremely well with the PX-25 and high-eff speakers. Also, plenty of drive for a passive preamp, I use an S&B TVC.