[Niteshade]

I was considering two new amplifier models that should intrigue you:

1. Single Ended 30 watt 572B Amplifier, integrated and non-integrated versions, stereo & monoblock versions as well.

2. Eight 6L6 (4 per side) 50 Watt 6L6 stereo amplifier or monoblocks, integrated and non-integrated options.

The medium power 572B SET looks like a good idea since it will be flexible with a greater range of speakers and 572B's are not as expensive as 300B's in dollars per watt, plus they offer a long service life. I have always liked direct heated triodes and have used them in the past with HF amplifiers. They never let me down.

For the second model, using four 6L6's to produce 50 watts will extend tube life. Our NS-100 is rated and tested to produce 50 watts with two 6L6GC's. While the tubes run cool in the NS-100, the tubes in the 8-tube 50 watt model would distribute the same amount of current 4 ways instead of 2. Longevity and not power is the reason behind this design. I have a thread called, "Photos of past projects" and the last amp posted has two 807's per channel producing 8 watts. The sound is excellent and tube temps are very low. The tubes shouldn't wear out for years.

Due to recent discussions, personal projects and feedback from people here, I would like to present some options:

1) Carbon composition resistors
2) Bybee filters
3) Audio coupling cap upgrades (paper in oil, whatever you want...)
4) Motor run capacitor/inductor based power supplies ***
5) Dual 5U4 rectifiers

***Struck me as a particularly excellent idea! Some of my older amps have filer caps in the 5-10uf range within a really good setup using high quality capacitors that have to be around 50 years old. The caps are still in excellent shape and the amps run quiet.

Performance and longevity are what these two models would be designed for. I feel that these two qualities built into an amplifier would make them worthy investments.

[vett93]

I'd like to see tube amps that can drive difficult loads. This means that higher current at low frequencies. If you can do that with a SET amp, more power to you. 

[Niteshade]

Somebody mentioned they would like to see a high current tube amplifier. The best way to get that would be to use a pair of 572B's in push-pull or a quad of KT88's per channel. Good industrial control transformer (s) for the HV would be a plus!  aa


Nothing wrong with lots & lots & lots of power! 

[JimJ]

Heck, I'd be interested in both!

572B SET monos as possible replacements for the SV811s, or maybe midbass amplifiers in an all-SET two-way biamped setup... Definitely a cool idea.

Nothing wrong with lots & lots & lots of power!

When are you coming out with 833A SET monos?  That kind of B+ voltage scares me a little 

As for options, I'd pay for improvements in component quality, but I'm not sure I'd pay for stuff like Bybee filters. Higher tolerance electrolytics and resistors, sure. And vacuum-tube rectification is always cool.

[vett93]

Right! No scary high voltage....

Differential balanced input option will be nice too.....

[Niteshade]

The HV wouldn't exceed1,000v with the 572B's in push-pull. I'll actually have to experiment with this to find the 'sweet spot' for the HV. It all depends on the output transformer that's chosen and its primary impedance. The SET design will run around 700-800 volts.

[JimJ]

Right! No scary high voltage....

Differential balanced input option will be nice too.....

Actually I kinda meant that in favor of HV designs, because I'd rather have someone else build it than trust my DIY skills over a kV

Having multiple output taps on the OPTs would be cool, as well.

[Niteshade]

I am surprised that not too many people chimed in. Maybe if I widened the scope to ask: What do you think would sell? Since Niteshade Audio is somewhat new, what kind of products would you believe to be good for the market- as well as their MSRP (low, medium or high end)? It might sound a little strange, a manufacturer asking these questions. BUT- your perception of the market and mine are different. Many companies have gone under from NOT ASKING these questions!!!

Your opinions do count- or else I wouldn't have taken the time to ask.

Thank you in advance.

[EDS_]

I am surprised that not too many people chimed in. Maybe if I widened the scope to ask: What do you think would sell? Since Niteshade Audio is somewhat new, what kind of products would you believe to be good for the market- as well as their MSRP (low, medium or high end)? It might sound a little strange, a manufacturer asking these questions. BUT- your perception of the market and mine are different. Many companies have gone under from NOT ASKING these questions!!!

Your opinions do count- or else I wouldn't have taken the time to ask.

Thank you in advance.

I'm a big four channel proponent (say 90% up front 10% behind for ambiance).

Here are some thoughts/wants....
1. Would it be practical and reasonable from a results perspective to build a balanced tube amp?  Seems like this would be uber-expensive.
2. An integrated with remote and both subwoofer out(s) and a set of variable full range outs?
3. An integrated featuring a defeat-able pre-amp section.
4. Switchable triode/UL (like the Cary SLI-80)


More later.

[Niteshade]

I need some clarification on a few things:

1. When you say a 'balanced amplifier' do you want XLR inputs?
2. Variable full range outs: Do you want seperate volume controls for each channel? (remotes only do two channels, but you can have two remotes to control front and rear speakers.

3. Defeatable preamp: Make an active preamp a passive one w/ a switch or to bypass tone controls?


Other than that- making a 4 or 5 channel tube amp is a good idea. Making one that's, say 40 watts/channel with 6L6's would be expensive and very heavy, but doable.

There's no problem installing a triode/UL switch an any amplifier.

[EDS_]

I need some clarification on a few things:

1. When you say a 'balanced amplifier' do you want XLR inputs?
2. Variable full range outs: Do you want seperate volume controls for each channel? (remotes only do two channels, but you can have two remotes to control front and rear speakers.

3. Defeatable preamp: Make an active preamp a passive one w/ a switch or to bypass tone controls?


Other than that- making a 4 or 5 channel tube amp is a good idea. Making one that's, say 40 watts/channel with 6L6's would be expensive and very heavy, but doable.

There's no problem installing a triode/UL switch an any amplifier.

Hey Blair,
1.  I'd like to know if a true balanced circuit tube amp is feasible?  XLRs into an unbalanced tube amp is a waste IMO.

The rest are likely unrelated to #1.
2.  If the "second" amp driven by the variable outs from the "first" amp had a remote-less volume control that would be no big deal.  However, maybe two identical integrated amps would work assuming variable outputs.
3.  Forget the defeat-able pre- I don't think the idea make much sense.

How about a for or five channel tube pre-amp w/remote with the ability to pot down C, LR and RR by hand?  Copeland makes something like this.

[Niteshade]

EDS_:

Your last post was just a quote. The rest didn't come through.

[EDS_]

EDS_:

Your last post was just a quote. The rest didn't come through.

Sorry.

[Niteshade]

EDS_,

Sorry for the confusion- it was me who was confused.

A tube amp can be made that's 100% balanced from 'front to back' . The shocking part is I don't believe it would be that expensive to make.
The other thing you mentioned - an amp with all variable outs sounds like a basic integrated amplifier to me- or a preamplifier with volume controls for each individual channel. Sure- that can be done too.

What are your other ideas?

Feedback from others would be good as well.

[vett93]

What does 100% balanced push-poll amp mean? Does it mean that each phase of the input signal drives the "push" or "poll" circuit?

Don't they get combined first and then split into two again?

[Niteshade]

He wants the input to remain balanced all the way to where it gets amplified. A balanced input is actually a phase splitter in a way because the output leads carry equal and opposite voltages.

The output transformer in a tube amp combines the balanced output  from the tubes on the primary side.

I think EDS wants to keep the input truely balanced all the way to the driver section without the use of a transformer.