New Stereomour Complete

[jtice]

I received my Stereomour kit a week ago and completed assembly and testing yesterday. This was my first build so I was more than a little paranoid that I'd end up with a mess I couldn't straighten out. Luckily, everything checked out on the first pass, with only the 230 voltages measuring a bit low, 350s and 380s a bit high but well within the 10-15% range, and both sides were virtually identical. I assembled it stock and have some russian teflon interstage and Obbligato parafeed caps on order. I'm quite pleased with what I'm hearing, even bone stock and with only a few hours of run in time! Detail, dynamics, separation, clarity, tone, imaging, smoothness are all improved greatly over the Scott 299b. Seems to have plenty of balls and drives the LaScalas to volumes I'd never need at about 1/3 up on the dial. There's only the tiniest hiss (with no music playing) when put my ear right into the mid horn, inaudible from a few feet away. I'd love to make it dead silent

[Grainger49]

John,

Congratulations!  How did the hum pot adjustments go?  I ask only because I tweaked mine down to 2mV in the left and 1mV in the right.  It takes the "tweaker's hand."  

I'm glad to see an "It worked the first time," post.  I would guess that for every Bottlehead kit that needs to be posted for a problem there are 20 that go together without a hitch.  Only Doc knows the percentages.

What I'm most impressed with is that the voltages from channel to channel are virtually identical.  That says everything went right.

Those 2A3s really sing!  Don't they?  The hiss will probably go away with 50 hours on the tubes.  Then you will start tube rolling and forget all about it.  

You can either PM Jim Rebman (jrebman) or post for his impressions of the JJ 2A3-40s.  He runs them in Paramours or Paramounts.  And, yes, the 12AT7 makes a difference.

You can use spade lugs on your speakers to get them out of the way, and use 90 degree adapters for your cables.

[tuffy_puppy]

please do consider obtaining one of the bottlehead power cords.  it will improve what the machine is producing currently.  don

[jtice]

Grainger,
I got them down to 2mV and 3mV. After I had it set up I moved them a little to see if that faint hiss would go away. I think it did improve the left side a bit. I guess I should reset them with the meter. Is this just about getting it as quiet as possible or are there other considerations, such as stressing tubes or other parts?

You're not the only one that was glad to see it worked the first time!!! Ha ha! I was dreading the thought of having to go back into it to track down a screwup

[Doc B.]

The hiss is most likely from the 12AT7s. Give them some time for the cathodes to form. They will probably quiet down. Amp looks great!

[shelby1420]

How many right angles do you need??

[jtice]

I need 2 good quality right angle plugs for music, and 4 that can be whatever for tuner and DVD. 

[kgoss]

Nice work on the amp it looks great!

One thing you could do with the speaker cables if you don't want to stack the spades is to install spades on your cables and get a pair of the Audioquest 1002 adapters to convert them to bananas.  You can get them in gold or silver finish http://home-audio.audioadvisor.com/search?w=banana+plugs

[jtice]

Kgoss, thanks for the link! That would indeed accomplish what I wanted... getting the cables to lay flat. It's a simple right-angle adaptor. I pretty much figured out that nobody sells a right angle banana. At least not at the better known parts places.

I just invested wasted a bunch of time obsessing over a plan and ordering parts for several sets of DiY interconnects and proper terminations for speaker cables. Looks like a parts list for an amp kit. I have never really been a "cable believer" but with Stereomour sounding more lovely by the day I rationalized that I just need to remove cables from the equation. It's bothersome to wonder if there are musical things in there that can't get out into the air because it's too crowded inside the cable. Plus, with Stereomour now being the best looking piece in the room, I figured I could at least satisfy myself on an aesthetic level by giving it some pretty cables to play with. By nature I'm too damn tight to buy boutique anything

[Fullrange]

Good job, the amp looks gorgeous , how did you get the brown powder coat on the top plate.

[jtice]

Good job, the amp looks gorgeous , how did you get the brown powder coat on the top plate.

Thanks! I'm pleased with how the top plate turned out. It's the rustoleum copper hammertone paint. There are about 6 or so coats on it. After the first coat, applied fairly heavy, I thought I was going to have to strip it and start over. The texture was uneven with thin places where the paint seemed not to take properly. I decided I had nothing to loose by adding additional coats and could still strip it and start again if necessary. So after 24 hours I applied a couple more lighter coats allowing 30-45 minutes between. Then Grainger told me I could perhaps accelerate the process by baking it in the oven at 150F for ten minutes. So I baked it at 170 for an hour ;-)  Then using a fresh can of paint I hit it with 2 more light coats and baked it again. I really don't know if the baking was key to getting the finish to look the way it does or if it was the multiple coats, going progressively lighter, or if it was the combination of the two. But I was finally satisfied with the texture and glad I stuck with it.

[jtice]

Tonight I replaced the 30 year old lamp cord between the tweets and networks in my LaScalas. I used single strands of twisted 24g solid core copper from a roll of CAT5 plenum. I don't know if it was the solid core, smaller gauge, purity, newness, twisted pair, or a combination, but the improvement is not subtle

[Doc B.]

I would suggest an experiment - clean the ends of the old speaker wire with steel wool or sandpaper, and try it again.

[jtice]

I would suggest an experiment - clean the ends of the old speaker wire with steel wool or sandpaper, and try it again.

Ah ha, so you're suggesting that the wire itself would not make a difference, but poor connections would? I suppose that could be. The old wires were soldered to the tweets with spades on the network end

[Doc B.]

I am only suggesting that it would be interesting to see if oxidation has anything to do with the sound. I am not suggesting that different wire does not make a difference, because it certainly can.