What A Difference An Amp Makes

[wilberforce]

My Beloved Sherwood S-5000II is on strike again--a horrible hum, even I had it recapped less than a year ago. I futzed around swapping the output tubes, but no dice. It's going to the tech tomorrow.

But I had set aside time to do some serious listening. I've got these new speakers that are the best I've ever had. So, I started dragging out the amps.

Just for fun, I hooked up the Lepai T-amp I got from Parts Express for $20 that has sounded pretty good just driving a pair of Minimus 7s out on the patio. Ugh. OK. waddya want for $20? People who describe any T-amp as "tube-like" haven't listened to tubes for a long time.

So rather than give it up for the night, I dragged out my Crown D150A. I recorded and mixed many albums using Crown D150s and DC300s. I thought, THIS will do until I get my tubes back.

NO. It wasn't much better than the T-amp. In fact, it had less bass. But it lacked the transparency and high end and overall sheen that the Sherwood tubes give. I was surprised. I had imagined that the Crown would at least be CLOSE. No. I tried lifting up the L-pads for more highs on my speakers to compensate, but that didn't get the sound.

Amazing. It was as if all of the magic smoke was let out. Cold, sterile, lifeless. It could be that the Crown is flatter than the Sherwood (I run the Sherwood flat, but who knows if it's flat just because the tone controls are at 12:00?) Maybe it's that synergy thing that we talk about from time to time. Normally, the Crown drives a pair of Yamaha NS10s for the classic 80's LA control room mix sound. Those two sound good together, but the NS10s are notoriously over-bright. It occurred to me that maybe the Crown is analogous to the NS10s. We used to say if you can get a mix sounding good on those, it'll sound good on anything. But when I want to kick back and just glory in the best sound I can get from my system, I don't worry about flat. I'm not going to mix with my horn speakers and a tube amp, that would be crazy. I just wanted to hear some sweet tones, and it was very surprising what a difference an amp makes.

These are the speakers:

http://www.audiokarma.org/forums/showthread.php?t=361690

 

[Arkay]

We often treat amps as less important to a system than other parts, simply because the source and speakers (the two transducers at the ends of the chain) have a more significant impact.

However, amps DO matter. Try inserting a broomstick in place of the amp, if you want to see just how much they can matter! While swapping out similar amps won't make much difference, swapping out very different amps will, and matching an amp with speakers can make a huge difference, as you've experienced.

Sorry to hear you couldn't get the sound you wanted for your listening session, and I hope you get your Sherwood back in shape, soon, to get back the sound you love.

:scratch2:... On the one hand, this experience should help you to better appreciate the good match that you already have there. On the other hand, this recognition of the difference the amp makes might also trigger an urge to see what improvements (rather than deterioration) you could get with yet a different amp... another ride on the old slippery slope, again?

 

[bowtie427ss]

If your D-150 is original and untouched, it's easily a decade past the need for a rebuild, and you shouldn't be objectively comparing it's sound to anything in it's present state.

Properly restored, the D-150 is an excellent sounding SS amp, too bad the mate IC-150 pre isn't on the same par.

 

[wilberforce]

If your D-150 is original and untouched, it's easily a decade past the need for a rebuild, and you shouldn't be objectively comparing it's sound to anything in it's present state.

Properly restored, the D-150 is an excellent sounding SS amp, too bad the mate IC-150 pre isn't on the same par.

Excellent point. It is original. OK, I'll get that thing re-built one of these days. Honestly, I was surprised, because as I said, Crown was about the only amp you'd find in LA studios in the 80's. And when paired with the NS10s, sounds about like what I remember.

But today the Sherwood is off to the tech.

 

[wilberforce]

:scratch2:... On the one hand, this experience should help you to better appreciate the good match that you already have there. On the other hand, this recognition of the difference the amp makes might also trigger an urge to see what improvements (rather than deterioration) you could get with yet a different amp... another ride on the old slippery slope, again?

I'd love to hear a SE amp with these speakers--they should be more than efficient enough to rock with just a few watts. I've been looking at Bottlehead's Stereomour. As much as I love the vintage stuff, it's a pain when they go down, because I'm not a tech. But having built twp Zilchlab crossovers, I've proven that I can follow instructions, and feel reasonably confident that I could build the Bottlehead.

Is that slope slippery enough for ya?

 

[fiddlefye]

Very cool speakers. They would be perfect for the tube amp indeed. What a fantastic project! Hope the Sherwood gets back in form ASAP.

 

[eteller]

Quoting a QSC engineer, if an amp is doing it's job you should not be able to hear a difference. I think a lot of home audio amps color the sound, just like tubes. I know my HK stuff sounds warmer than other gear I've tried. Running my tube phono pre into my HK AVR then to my QSC retains the traits I want to keep.

 

[cmb3366]

I've been in your position before and it is not fun. The power switch on my SET amp gave up the ghost about a month or so back. I took it to my dealer who ordered a replacement and sent me home with a NAD 315bee to get me through till it was repaired.

Nowhere even close to what I was used to listening to, it was a hard week or two, and it made me appreciate my main amp all the more when I got it back.

 

[wilberforce]

Quoting a QSC engineer, if an amp is doing it's job you should not be able to hear a difference. I think a lot of home audio amps color the sound, just like tubes. I know my HK stuff sounds warmer than other gear I've tried. Running my tube phono pre into my HK AVR then to my QSC retains the traits I want to keep.

Yeah, I was always in the camp that said the amp doesn't matter as long as it's not screwing up. And this thread is certainly not meant to say that tubes are inherently better than SS. I've heard a lot of tube amps that, while charming, colored the sound to a degree that's silly. There's a reason that guitar players want tubes--it's for that sound.

But the Sherwood is a different animal. It doesn't get tubby with 2nd harmonics like so many tubes, I don't hear a lot of distortion at 400 hZ that people always describe as 'warm,' it just sounds amazingly CLEAR, and clean, and has more top end than any amp I've tried to substitute for it.

Well, it went to the tech today. Apparently, the moron that re-capped it for me last year didn't change out the filter caps. Sheesh, even I know you have to change those--I just don't know how to do it. That's the source of the hum. I'll have it back next week.

But no one has taken my bait about using a SE 2A3 amp with these speakers. Are those amps really what people say they are? I've read accounts of people bursting into tears as though they were hearing music for the first time. I mean really, the accolades for SE 2A3 amps are wild. True or hyperbole? I'm intrigued, to the point that I'm considering buying the Bottlehead Stereomour kit at $750 large, but I'd hate to be disappointed. Not only is that a lot of money, it would mean many nights of hair pulling and bewilderment.

SE 2a3 people, thoughts?

 

[wilberforce]

I've been in your position before and it is not fun. The power switch on my SET amp gave up the ghost about a month or so back. I took it to my dealer who ordered a replacement and sent me home with a NAD 315bee to get me through till it was repaired.

Nowhere even close to what I was used to listening to, it was a hard week or two, and it made me appreciate my main amp all the more when I got it back.

Yeah. These aren't bad amps I'm substituting, but the difference is amazing. It's as though all the air was let out. Maybe the Crown has drifted out of spec (it sounds good with the NS10s), but I've tried two T-amps that sound good with other speakers, and I'm not EVEN going to bother hooking them up to the Pioneer A/V receiver.

There might be something to that synergy thing we talk about from time to time.

 

[JohnVF]

I totally agree with the different flavors amps bring. I keep a small-ish collection of amps around, both tube and solid state, and use them to change things around, to suit my mood. Its sort of my version of tone controls, I guess.

 

[cmb3366]

But no one has taken my bait about using a SE 2A3 amp with these speakers. Are those amps really what people say they are? I've read accounts of people bursting into tears as though they were hearing music for the first time. I mean really, the accolades for SE 2A3 amps are wild. True or hyperbole? I'm intrigued, to the point that I'm considering buying the Bottlehead Stereomour kit at $750 large, but I'd hate to be disappointed. Not only is that a lot of money, it would mean many nights of hair pulling and bewilderment.

SE 2a3 people, thoughts?

No SE 2a3 experience, but I can tell you that low/no NFB SET amp are a wildly different presentation than any other amp I've heard, which runs the gamut from low end SS to PP tubes worth more than a nice car. If you like air around instruments and killer dynamics, SET is where it's at.

As you can tell from my sig, my amp runs 6c33b's which are very muscular triodes at 15 watts a side, if you've got the sensitivity for 2a3's, which it would appear you do, there is no reason to pay for the extra muscle, try a bottlehead or decware kit and prepare to smile.

BTW, don't assume your crown amp is out of spec, IME that's just how they sound. I had a SL-2/PL-200 rig a few years ago that was just as flat and sterile as you describe.

 

[gmku]

I consider the amp (for me it's an integrated amp or a receiver) the most important piece of the system. Next would be speakers, but the best speakers will sound like crap if the power source is crap.

 

[Dr Tinear]

No SE 2a3 experience, but I can tell you that low/no NFB SET amp are a wildly different presentation than any other amp I've heard, which runs the gamut from low end SS to PP tubes worth more than a nice car. If you like air around instruments and killer dynamics, SET is where it's at. ...

That depends on the SET amp and the speakers to which it's mated. I've heard SET amps that sounded startlingly realistic to me on speakers with a benign impedance curve and a reasonably high sensitivity. I've also heard SET amps that sounded veiled, rolled off at both frequency extremes, and unacceptably colored in the midrange, even on speakers that should have been easy for them to drive.

I briefly tried a friend's SET amp in my own system last year. It was about 10 years old and had been on Stereophile's Recommended Components list. My friend's amp had just finished getting a repair and an operational check-out (including a bias check) on my bench, so I'm confident that it was working as its designers intended. Driving my Von Schweikert VR-4s, the amp sounded wonderful on female vocals. When I changed CDs to a high-quality recording of large-scale orchestra music, the presentation fell apart. The amp was running nowhere close to its power rating, but it still delivered a congested midrange, a rolled-off top, and a noticeable peak in the mid-bass. Going back to my Van Alstine power MOSFET amp restored the neutral, dynamic sound that I'm accustomed to hearing from my system.

 

[Mister Pig]

I Own 300B an 2A3 Based Amps

The 300B Electra Print stack is my daily driver, but I have a 2A3 integrated as a back up.

When dealing with a low powered SET amp, its mandatory to have a fairly efficient speaker with a benign impedance curve. The fewer cross over parts the better, although thats not mandatory. I have friends who run horns that require steep slopes in the crossover, and it works well with 2a3 based amps.

SET amps when properly done are transparent and realistic in a way that few other types of speaker/amp combos can sound. In some ways it is similar to planar speakers, but can do mega and mirco dynamics in a way that the panel speakers cannot. Of course there are good and bad examples of SET, so be aware of what you buy. Like with any tube amp, iron is the key, get a kit with good iron and thats half the battle.

2A3 amps are low powered, and few speakers are going to perform like a champion in the bass department with this type of amp. Many people run a sub to augment the bottom end, especially with the lowest of the low powered tube amps. If you change to a 300B it is possible to run full range, if you got the right speaker. But the 300B has a different presentation than the 2A3. Both can be exquisite, but are shaded differently.

The Bottlehead stuff is very nice, a good kit to build. Electra Print also supports the DIY community, and can offer a good package. You would have to build your own base though, I don't think the kit is as complete.

Regards
Mister Pig

 

[cmb3366]

ansparent and realistic in a way that few other types of speaker/amp combos can sound. In some ways it is similar to planar speakers, but can do mega and mirco dynamics in a way that the panel speakers cannot. Of course there are good and bad examples of SET, so be aware of what you buy. Like with any tube amp, iron is the key, get a kit with good iron and thats half the battle.

It's interesting that you say that because the only rig's I've ever heard that had a presentation similar to my SET and horns were Magnepan 20.1 and a pair or the better Martin Logans (name escapes me) driven by megabuck mac amps. They nail the air, but didn't quite get the snappy dynamics. Just found it neat that someone else's experience so closely mirrors my own.

I think You and Tinear have it right on the flat impedance and simple crossovers, I've only run my SET on a couple different pairs of speakers, but I keep coming back to klipsch for some reason. That said, I have been impressed with what I heard at a local dealer with my amp on a pair of the new goldenear Triton towers, which are very different from my horns.

Bottom line, IME if you have horns as the OP does, SET topology provides something special that is hard to match for realism.