Serious Modifications

[Paul Birkeland]

Hey Randy - There are Paramounts in my future too.  Is there any way to use the Stereomour as a pre-amp, beyond just passive control?

Theoretically there could be a way to wire it for 45's with a single shunt regulated B+ supply using a completely different power supply, and some kind of DC on the 2A3 filaments.  This would turn the circuit into a preamp, but I'd expect the parts to be very expensive (maybe more than the Stereomour was in the first place), and there's a good possibility that a lot of R&D work would be required to get good results.

(Remember, a Quickie is only $99)

 

[drewh1]

Well I think knew the answer to that question anyway 

I will likely build the BeePre next. I have been wanting to use my expensive balanced interconnects anyway. All of my current gear is balanced and I got suckered into buying these things! Then I'll build the the Paramounts (after I let Randy figure everything out)

 

[earwaxxer]

Balanced has piqued my curiosity lately as well. I was previously a skeptic.

On a lark I bought some Blue Jeans balanced interconnects about 6 mo. ago since all of my gear has balanced outputs. I was pleasantly surprised. Thats why I retired my quickie there for a spell. The quickie is back in now with the 'new' digital front end. Of course the proposition of going full balanced with beepree is gnawing. It would be cool if someone could give their impressions of the prebee sound over balanced vs. unbalanced.

 

[drewh1]

I used to be a musician and so was used to always using balanced cables - I kind of always thought it was the best way to go.

My Ayre equipment is balanced all the way through - I do imagine? I notice a difference with the balanced cables. I think that is specific to the Ayre gear and isn't necessarily strictly because of the balanced interconnects.  having said that, I like the sound of the Stereomour better than the Ayre with my DIY magnet wire single ended interconnects so that says something . . .

I think we hijacked Randy's thread 

 

[rlyach]

No problem hijacking the thread. I have literally run into a wall anyway. The more I dig the more I find out how little I know about amp design. I attempted to do my own simple parafeed circuit. I actually designed it around iron that I could get easily. Then I submitted it to a friend of a friend who builds custom iron and designs. He thought my circuit was a good attempt "for someone who is new to tubes," but then proceeded to point out several issues. I now know I don't really understand reactive plate loads, and I am finding I don't have time or the resources to find out. If I really wanted to design my own amp I will need to build, test, change, test, change, test... I guess that is why BottleHead amps sound so good. They have put in the time and effort, and they have built the knowledge to design something that works and sounds amazing to boot. I have resigned myself to purchasing an integrated kit based on the 300B just to satisfy my need to build something else. Besides, I need to replace my solid state amp (Linn LK140 if anyone is interested  )

 

[drewh1]

I hear ya Randy - Feelin your dilemna - thinking about selling my Ayre but need it right now for videos. I definitely don't have enough juice with the stereomour for videos. I guess the output is much lower from my DVD player.

I liked your idea about building the Paramounts on one platform. I am used to an integrated amp and struggling with whether to have all the different components needed for the monoblocks.  Sounded like a reasonable compromise.

Let us know what you build.  BTW, i am lovin having a remote for the Stereomour, now I can sit back and relax . . .

 

[rlyach]

Drew,

Your woodworking skills have inspired me. I am getting ready to build another Stereomour kit for my Pastor. We purchased a pair of Hoyt Bedford monitors for his amp, so I purchased this nice piece of Sycamore to match. I plan on finishing with tong oil and wax, as per a woodworker I met in the Woodworkers Source. This should look cool, especially with the dark edge. I plan on doing a 1/4 or 3/8 round over around the top outside edge as well. Plus I am making it 1/2 inch taller than the supplied kit base.

Incidentally, I have chosen my next amp project but it is not a BottleHead kit. I really wanted an integrated stereo amp based on 300B's

 

[drewh1]

that is a beautiful piece of wood - and rounding the edges will add a great finished look. Good call to make it deeper - I am glad I made my base a bit deeper (4"). it easily accomodates the stepper motor I added.

Post pictures when you are done!

 

[rlyach]

Drew,

Here is the finished base. This is the first time I have used wax and I must say that I like using it. Much better for the wood and less messy. Plus I was able to use a buffing pad on a drill to give it a nice sheen. Now I am waiting for the kit to come so I can start building.

 

[drewh1]

that's gorgeous, I really like the rounded top edge. I also think the extra depth has an elegance too it, as well as allowing more room for large expensive caps!

very nice work - be careful, you might have to try making your own tubes soon    Still awaiting my new "improved" crossovers. I almost bought a couple of Clarity MR caps for the coupling but am saving my money for the paramounts.

Oh, I picked up a matched pair of Telefunken NOS tubes, don't need two, just happened to be a good deal. Let me know if you want to try one in your Stereomour, I'll send you one so you can compare. So far I like the stock tube alot though.

drew.

 

[4krow]

Randy,

  I KNEW that was sycamore! It is one of my alltime favorite grains. The grain seems to interlock.
  Now, I get the idea that you want to customize an amp, but my question is, since you will be building speakers that are 97db sensitive, why would you need more than a couple of watts?
  This has become a fascinating thread by the way.

 

[drewh1]

Hey Greg,

You might have Randy and I confused - I was going to build some FR Metronomes but am holding off now. Everything sounds too damn good. The GMA's are sounding great and loud enough. Randy is using Orca's and is super pleased with them.

I just want to build more stuff, and I can afford it  if can just sell this other stuff . . .

drew.

 

[rlyach]

Yes... I wanted to build some speakers but I was having trouble finding a full range driver and I am afraid of veneer. I was trying to design my own integrated stereo 300B system (using a parafeed topology) but I realized I don't know enough yet. I also don't have the funds to experiment with different components. So I ended up purchasing a 300B kit which uses a direct drive topology and a two stage pre-amp circuit. I also ordered a pair of Omega Super 3Ss to go with it. The Omega's are 94 or 94.5 db efficient so they should be a good match for the 300B's. By the way, the Orcas with the Stereomour keep getting better. The more the system breaks in the better the response. The bass response is around 75 Hz even though the driver is only rated at 100 Hz. The ported cabinets are very well tuned.

 

[4krow]

Yah, at least I got part of it right. The Sycamore really looks good for that base. I still have some in my stash. I have had it too long for it to just sit there any longer.

 

[rlyach]

Drew,

Thanks for the offer of the tube. To tell you the truth, I have not even listened to the kit tubes yet. I plugged them in to do the final voltage checks and then immediately switch to the JJ 40W tubes I purchased. I have only listened to the JJ's. They also have a larger bottle than the standard 2A3. I think it is the same size as the 300B bottle. I think they sound very good and now that they are getting broken in, I don't want to switch them out. I will keep the Sovteks for a future use.

 

[drewh1]

FYI - it is a driver tube  - I am playing around with driver tubes because it is fairly inexpensive! Can't afford those big guys and still really thinking about the next build.

 

[rlyach]

Sorry, I was confused on terminology. I assumed driver tubes and power tubes were synonyms. My bad  ;D. I always called this the pre-amp tube or the gain stage. I guess I have never heard it called a driver tube before. Anyway, in reference to the driver tube I am in the same boat. I am using a JJ gold pin 12AT7 and have never listened to the kit tube. Maybe I should! I am so satisfied with the current configuration that it never occurred to me to change it.

 

[drewh1]

I had a bad 12at7 tube shipped and replaced it with the JJ Goldpin too.  When I got the stock tube last week, I dropped it in just to see if I could hear a difference. I really like the stock tube better than the JJ. I noticed a lot more clarity and separation, better all around.  So I have the JJ sitting in a box now. My experience anyway.

 

[4krow]

I have to agree about stock tubes. It's not like a so-so product was sent. Probably had an evaluation before it was chosen to begin with. I have been rolling in my Quickie, and the stock tube rates quite high. I was just lucky enough to get a couple of NOS Telefunkins that have the edge over some others that I have tried.

 

[drewh1]

I am trying a NOS Telefunken next, I would also like to try the Mullard (I hear that is what Doc uses!).  I will have a spare Telefunken if anyone wants to trade for a Mullard (just to try them out).

Those about the only ones I am interested in right now. For me it is just to try some different things to hear them, not really feeling the need to improve necessarily.