Stereomour vs. nickel-ironed SEX

[Dr. Toobz]

Every year since the Stereomour was released, I keep saying I'm going to build one. But it's hard to justify the expense when my SEX amp sounds so good!

Recently, I installed the full nickel iron upgrade from MagneQuest, which has added an honesty and sweetness to the midrange that I've never heard before. That said, would there still be any point to moving up (or over?) to an AC-heated DHT amp when my IDHT has $450 of magnetics under the hood? Can the Stereomour truly "one up" this arrangement in terms of sound quality? (I find it hard to believe!) Or would it more likely be a lateral move, netting a bit more power, but not much improvement in tonality or sound quality in general?

I don't need more wattage at this point, as I rarely listen above 1/8 to 1/4W in my small apartment over 99dB/Wm speakers. My only other concern with the Stereomour is the possibility of hum, since the speakers are just under that magic 100dB/Wm mark where AC heating starts to become a problem on lesser amps. The SEX amp is absolutely dead quiet on the speakers, even more so than the solid-state amp it replaced.

[BNAL]

I would have thought the same thing about being able to improve an already great sounding amp, but there is something about DHTs. DHTs seem to be more transparent then indirectly heated tubes.

I have the S.E.X. amp with MQ nickel pinstripe iron and Paramounts with with BH iron and prefer the Paramounts for listening. I'm sure the Stereomour will be the same way. There is also the different camps of thought about which is better A/C or D/C heating.

I use my S.E.X. amp exclusively for headphones now and love it.

[Doc B.]

Yeah, what Brad said. The 2A3 amp will have a little better resolution and delicacy. We have a customer or two using Stereomour with high sensitivity speakers (IIRC one has horns over 100dB) and hum does not seem to be a problem.

[smithanh]

I just finished a Stereomour and am playing it through Klipsch LaScalas (104 db sensitivity) and have no problem with hum.

[Grainger49]

Angelo,

What you will hear is the difference in the tubes' characters.  That said, the nickel brings you closer to what the tube really sounds like.  So you would be off on a new journey.  I would expect that you would like the Stereomour, maybe even modded to 45 outputs since you are happy with the power of the SEX amp.  Then you would want nickel in it too.

[Paul Joppa]

For what it's worth, here's some history:

The Paramour (grandfather of the Stereomour) was my first design for Bottlehead. I was just a club member in those days; but at some point Dan challenged me to design a DHT amp that could sell for a similar price as the SEX amp. (At that time, the original SEX amp was monoblocks with paralleled 6DN7s - the modern SEX amp is  different, though the tube is the same.) There was enough improvement that Dan took it to market, whether due to the directly heated triode or the greater linearity or some other "DHT magic" I'm still not sure about. Paramour and its descendents  has been on the market ever since, with only minor adjustments to the basic design.

[Dr. Toobz]

Thanks for the advice, guys. I'm usually the one expected to "dole out advice," but not when it comes to tubes!

I'm going to take the jump into the world of DHT's, and recently emailed the Queen about lead time on the Stereomour. As for the SEX amp, I'm likely going to pawn off the nickel set and re-do the amp in stock form for my father's birthday later this year. He's an electrician and always asking about my tube adventures, and I know he'd like a good, tubed amp for his computer room/study! Without the C4S boards and fancy transformers, the SEX tends to sound full and warm, which will work great with a pair of tiny bookshelf speakers, as well as the Grado headphones that I bought him a year or two ago.

If anybody is interested in my nickel set, please PM me.....

[Paul Birkeland]

If you are harvesting the iron from the SEX amp and returning it to stock, I would recommend contacting the Queen about the new proprietary Bottlehead output transformers if you do not already have them.  They will get you much further than the Specos at a reasonable price. 

-PB

[Dr. Toobz]

I'd thought about that, but I was under the impression that they are not available ala carte, at least not yet. Maybe that will change by summer?

[Paul Birkeland]

While this is true, you may find a fellow forum member who upgraded and has surplus stock iron.

[fullheadofnothing]

The iron upgrade is coming very soon. The last conversation about it suggested that pricing needed to be figured out. The instructions are written and will be posted online like the MQ iron. Dan has got a ton of irons in the fire right now, so I don't want to speculate on the timing, but it should be relatively soon.

[Dr. Toobz]

I'll have to see about the BH iron upgrade once the amp is rebuilt. Honestly, I am purposely trying for a "tubey," thick sound for my dad's amp, considering that he will be using tiny speakers, Grados for headphones (which tend to sound harsh with poor sources) and no audiophile sources - just the line-out from an iMac. The stock SEX, sans spendy transformers and C4S boards, sounded warm and inviting when I built it, and that's the sound my father remembers.

My Stereomour has been ordered, and I've come up with what I think is a good solution to my need for a pre-out to run to the Crack amp that will take the place of the SEX for headphone duty: instead of RCA plugs in the last set of holes, I'm going to put in two stereo 1/4" headphone jacks, Nuetrik of course, and will place a red cap on one of them to denote its use as a pre-out (http://www.neutrik.com/en/audio/plugs-and-jacks/jacks/jack-accessories/). That way, I don't lose the third input, even though it's very unlikely I'll ever need it, and I can have a pre-out without drilling holes and messing up the plate. I already have some 1/4" stereo to RCA cables, so I think this will work out quite well.

[Natural Sound]

and no audiophile sources - just the line-out from an iMac.

You might want to try to talk him into an inexpensive DAC. That's a no brainier and easy to impliment upgrade to his source. You should be able to get something for $150 or so.