AudioCircle

Audio/Video Gear and Systems => Owner's Circles => Niteshade Audio => Topic started by: Niteshade on 4 Apr 2010, 12:51 pm

Title: Niteshade Audio NS-SEP20 6L6 & EL34 Single Ended Parallel Stereo Amp
Post by: Niteshade on 4 Apr 2010, 12:51 pm
(http://www.audiocircle.com/image.php?id=28559)
(http://www.audiocircle.com/image.php?id=28560)

Crimson red pearl, perfectly figured tiger maple, point to point wiring, James outputs, 1940's enhanced power supply with 4-stage filtration.

That's just a few of the highlights!

This is our new flagship SEP and it has a NOS Stancor power transformer.

Stay tuned for more features & spec's!

Title: Re: We've taken Single Ended to new heights!
Post by: Pez on 4 Apr 2010, 05:03 pm
Gorgeous! Is it possible to get this amp with a triode switch?
Title: Re: We've taking Single Ended to new heights!
Post by: bummrush on 4 Apr 2010, 05:43 pm
  beautiful!!!!!!!,,,i suppose its hard to do but i'll ask anyway how do your tubes amps compare to the digital amps you seem to be embracing quite a bit.And really dont you think the digital wallop that comes out of the digital amps a bit much?
Title: Re: We've taking Single Ended to new heights!
Post by: Niteshade on 4 Apr 2010, 05:50 pm
It could be made with a triode switch but the way it's wired now is much better. I use a tetrode mode configuration that outperforms triode mode in every sonic aspect. Amplifier efficiency is increased as well, making the tubes last much longer. 
Title: Re: We've taking Single Ended to new heights!
Post by: bummrush on 4 Apr 2010, 07:11 pm
   Thanks have a great dinner.I had a couple dig amp.and yes they do perform good,but even for my Legacy studios,which go down to 40,they are small square power houses of bass,i just found the bass way to much,and part of it could have been my room,,like 11 by 9,ceiling 8 ft.So much of bass depends on the recording anyway.
Title: Re: We've taking Single Ended to new heights!
Post by: Niteshade on 5 Apr 2010, 12:10 am
I have a thread on this subject: http://www.audiocircle.com/index.php?topic=79188.0

What it comes down to is this: Every kind of amp circuit has its own interpretation of what's coming across the input. Class D is more concrete than most amplifiers. They're fast and have very good control over speaker cones. That's all the drivers: Woofers, midranges and tweeters. This control is what I believe makes them sound more abrupt and not as contiguous as a tube amplifier. Is that bad? Is "brick wall control" better than having a little elasticity?

Both amps are very revealing of the source. Both amps have low noise floors. A tube amp has more elasticity within its circuit, meaning less speaker control. That translates into playback that's more fluid, organic.

I thoroughly enjoy Class D amps AND tube amps. These two are my favorites. People, including myself say Class D is tube-like. When I say it, I'm referring to the amp's ability to pick up subtle nuances within music. I like their resolution- it's similar to a tube amp's. I employ methods which greatly enhance a tube amplifier's performance via enhanced sound through efficient tube operation. Efficiency is something Class D's are well noted for too.


  beautiful!!!!!!!,,,i suppose its hard to do but i'll ask anyway how do your tubes amps compare to the digital amps you seem to be embracing quite a bit.And really dont you think the digital wallop that comes out of the digital amps a bit much?
Title: Re: We're taking Single Ended to new heights!
Post by: Niteshade on 5 Apr 2010, 11:24 am
(http://www.audiocircle.com/image.php?id=28593)
(http://www.audiocircle.com/image.php?id=28594)

There is a switch behind the filter choke. You have a choice between tube and solid state rectification!

The other controls are for tunable biasing and feedback level. I like it when customizations can be made by turning a control or flipping a switch.

More photos and features are coming up!

Title: Re: We're taking Single Ended to new heights!
Post by: Niteshade on 5 Apr 2010, 10:08 pm
Do you have questions about how SEP amplification performs versus standard single ended technology? It has nothing to do with push-pull amplifiers and does not share any common ground with them except the number of power tubes used and that slips away when an odd number of power tubes can be used.

I know this must be new to many people.
Title: Re: Our New Flagship SEP Tube Stereo Amplifier. Have you seen it?
Post by: mjosef on 6 Apr 2010, 03:01 am
Only in pictures man...is it real?
Title: Re: Our New Flagship SEP Tube Stereo Amplifier. Have you seen it?
Post by: Pez on 6 Apr 2010, 03:10 am
It looks like you are using 6L6 power tubes and 6NS7 for a driver? Also what is the rectifier? I'm guessing (probably wrong) 5U4?
Title: Re: Our New Flagship SEP Tube Stereo Amplifier. Have you seen it?
Post by: Tyson on 6 Apr 2010, 03:13 am
Yes, single ended Parallel is not the same as Push Pull.
Title: Re: Our New Flagship SEP Tube Stereo Amplifier. Have you seen it?
Post by: Pez on 6 Apr 2010, 04:06 am
Disregard my question. I just went to your website (http://sites.google.com/site/niteshadeaudio/Home/niteshade-amplifiers/single-ended-amplifiers) and answered my own question... I'm just resourceful like that.  :duh: :)

But also it feels so good to be right.  8) :lol:
Title: Re: Our New Flagship SEP Tube Stereo Amplifier. Have you seen it?
Post by: Niteshade on 6 Apr 2010, 11:53 am
Yes, it is real. Believe me, I know! It's a VERY expensive amp to make and it took allot of planning in terms of aesthetics and the new circuit being used. High powered single ended amps are more difficult to make and design than low powered ones. I will have an interior photo soon and discuss some of its qualities.

Only in pictures man...is it real?
Title: Re: Our New Flagship SEP Tube Stereo Amplifier. Have you seen it?
Post by: Niteshade on 8 Apr 2010, 02:28 am
Here is a detailed description of the SEP20:

Single ended amplifiers have a special place in people’s harts. What many people do not like is the single-digit wattage ratings. There is more to wattage than just how loud an amplifier can get. In fact, loudness is always secondary to performance. A good, wide bandwidth amplifier will produce a wide sound stage containing vertical, horizontal and forward dimensions. To effectively provide all three dimensions, it takes some power. Our SEP-25 provides 25 solid RMS watts per channel from 20-20,000hz simultaneously, not just at 1khz. I never measure my amplifiers at a single frequency because that is an artificial rating. Only wide bandwidth measurements are taken with real, high quality, well recorded music.

SEP stands for Single Ended Parallel. Even though there are two power tubes per channel, this has nothing remotely to do with push pull. The great thing about SEP technology is that we can increase the output power by adding as many tubes as necessary! Odd tube numbers work as well as even ones. We can make SEP’s up to 50 watts or more per channel. A SEP amplifier is derived from a standard single ended design. In the amplifier shown, each channel has two power tubes driven in parallel. In effect, it is the same as one single giant power tube. Clarity, the ability to sustain bass notes, midrange richness and high frequency purity are all increased many times over a standard single ended design. I am quite familiar with amplifiers using 845’s, 813’s, etc… They do sound good, but are exceptionally expensive if you want true high end representations. Our SEP-25 offers more power than most single tube, high end single ended amplifiers and will perform as well as or better than SE’s costing twice as much.

Development began around a set of James output transformers. These potted outputs are extremely high quality. Construction is impeccable and materials used are the finest grade. You will not find too many differences between these and vintage UTC brand outputs. To make this amplifier unique, I used a NOS Stancor power transformer with a solid copper EMI suppressor band. This transformer was never used. I pulled it right out of its original box. All the voltages it provides are ideal for this amp and it provides more filament current than necessary. It was being saved for something special, so it went into this new 2010 SEP flagship. All wiring is point to point with special double insulated tube amplifier wire that is cotton covered. Nothing finer can be used in a tube amplifier.

Our flagship SEP features a power supply that has our 1940’s upgrade. In the 1940’s, high grade tube power supplies were made to operate with heavy chokes and solid capacitors. The reason why we adopted these practices is because we noticed these units can remain functional for half a century and when made properly, are extremely quiet. Our 1940’s equipped amplifiers have heavy chokes as well as solid capacitor primary filters along with added filtration stages, numbering four total. We designed the rest of the amplifier to take advantage of this special power supply. The end result is a very low noise floor, increased amplifier efficiency and longer lasting tubes. Along with this upgrade, you will have the option to go between tube and solid state rectification with the flip of a switch.

Other features include tunable biasing and variable feedback. Tunable biasing is a DC biasing method that does not require a volt meter to use. Biasing is calibrated and marked during burn-in. There is leeway on either side of this mark so you can fine tune the tubes to your liking. The rule is this: Locate the position that sounds best and produces the least amount of heat from the power tubes. That’s all there is to it! Variable feedback insures a perfect interface between amplifier and speaker system. Adjust this control to your liking. When completely off, there is zero loop feedback.

The amplifier is finished with solid highly figured tiger ample on three sides that is completely hand made and utilizes dove tail joints on the front corners. We used crimson red pearl for the interior finish.

Specifications:
*James potted output transformers
*20 watts per channel into 4 and 8 ohm loads
*Frequency response: 20 to 20,000hz
*High current power supply with 1940's upgrade and additional filtering above that
*5AR4/5U4 tube rectification or solid state rectification with the flip of a switch
*6SN7 high resolution drive circuit6L6 and El34/6CA7 compatible power tube selection
*Tunable biasing: Perfectly bias the tubes without a volt meter, quickly and easily
*Variable feedback: Makes it possible to exactly match the amp to your speakers
*IEC power socket
*Dimensions: 17x10x8 inches @ 40lbs