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Bottlehead 2A3 kit


Daddy Dee

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Have been wanting to build a kit for some time and think this one seems to be simple enough for beginners. Years ago a forum member sent a pair of Paramours and I listened to them for a good while. Really liked the sound and found them comparable to Wright 2A3's which I ended up purchasing and using for a season with LaScalas and Khorns.

Because of small quarters had been listening just to Heresys for about six years, but now have space for LaScalas and have been really enjoying them.

Definitely qualify as a beginner. Have just acquired a soldering station and multi meter, so think I've about got things together to proceed. Daughter and son in law will be here Thanksgiving. He is an engineer and will be around for support. Not sure I can have the Bottlehead kit here by then, though.

What I've selected is the Stereomour amp, which they've had out for just a few years. It is described as something like the original, but improved parafeed with better iron Paramour which had been sold before putting out the current Paramour kit which is now higher end than before.

Having listened to the original Paramours for some time and liking them, think that is a choice that should have a pleasing end result.

Haven't ordered the kit yet and thought I'd ask forum members for any advice about kit building and any other recommendations for kits. Have seen the Japanese Elekit, and it looks pretty cool, but I have no experience with the sound and the building and troubleshooting support of the Bottlehead crowd seems pretty good.

Also have thought about one of the modern ST-70 or Mark III kits, but am already listening to a Baldwin 6L6 which sounds pretty good. None of these will bring the sweet sound of flea powered SET. Maybe for another season.

Any advisement is appreciated.

http://www.bottlehead.com/store.php?crn=44&rn=447&action=show_detail

Oh, one other thing. The Stereomour is designed so that a rather small change can allow the use of 45 tubes. I'm wondering if the amp might be built to allow some sort of switch or otherwise solderless solution to switch back and forth between 2A3 and 45 mode.

Thanks in advance for any help!

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Sounds like fun. I think several here have built them so do a search.
Pinout locations between the 2A3 and the 45 are both the same so I
would suspect you could build it so flipping a switch would allow you to
change tubes, but I'm not at all sure about biasing(if biasing is even
needed in a SE configuration). This is Thebes talking technical so beware, brother, beware!

For soldering practice go
to your local Radio Shack and pick up a few cheap components (resistors
etc.) and one of the breadboards they sell for cheap and you can solder
and desolder to your hearts content without fear of breaking anything.

See here for examples of actual RatShack breadboards:

http://www.radioshack.com/family/index.jsp?categoryId=2032265

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For soldering practice go
to your local Radio Shack and pick up a few cheap components (resistors
etc.) and one of the breadboards they sell for cheap and you can solder
and desolder to your hearts content without fear of breaking anything.

Those boards are really hard to solder on. Using all the correct solder and toolds, I've had a lot of trouble using their boards. On the other hand, once you can learn to sold on them, you'll probably have no trouble with a Bottlehead kit.

Bruce

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I all ways wanted to try one of their kits, I think it should't be to hard. Dee if you want I might have a couple of boards you can try on. I had made a couple of these.

http://diyaudioprojects.com/Solid/12AU7-IRF510-LM317-Headamp/'>http://diyaudioprojects.com/Solid/12AU7-IRF510-LM317-Headamp/

My first one I messed up on and print on the second board didn't turn out as good as I wanted I have to drill out the holes for the second but you can stuff it with your hearts content or even follow the design and see if you can make it work. I picked up all the parts online and from the shack for less then 50.00. I made the boards from scratch its kind of tricky but when done right its fun and neat for the fact that you made your own board.

Heres the link from the main sight there are a lot of other projects out there the might be up your ally.

http://diyaudioprojects.com/

PM me your address if your interested.

Nick

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Gentlemen, thanks for your advice here.



Bruce what do you make of the BH boards being difficult to solder? What type solder and tips do they recommend?

I imagine the BH boards are fine. The problem is the Radio Shack boards. They are the ones that are awful. Didn't mean to confuse you. I did a bunch of prototyping for someone and he provided RS boards. They were a little difficult to use.

Always thought a BH kit would be nice to try myself. Since I got the Moondogs, I've cooled my jets a bit. Still have to finish my ST-70 board... [:(] To many half baked projects I've started...

Bruce

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Daddy Dee,

I have built 3 Bottlehead kits.

The preamp called Foreplay. Added many upgrades.

Two monoblock Paramour 2A3 amplifiers. Added very few upgrades.

One Seduction Phono preamp (their first edition in 2003). No upgrades added.

The kits I built were more point to point. The circuit boards came later, so I cannot speak about them.

As you saw from the Stereomour underpanel picture, it is well laid out with lots of space around most of the soldering connections that would be required to be performed while under the faceplate.

The circuit boards will be soldered off the board.

The two pots in the middle area next to the tube sockets are for balancing the filament voltage for hum reduction on each 2A3.

The aluminum faceplate is often painted, but search out the best way to paint aluminum. Mine turned out OK.

The sound I got was simply wonderful when connected to my 89 LaScalas. 3.5 watts from the 2A3 tubes gave me plenty of power.

Soldering.........is an acquired skill. The more you practice the better you become. Clean your wires before you connect then and the soldering point with alcohol. Make a firm/tight connection before soldering and you should have no cold solder joints.

When I built my kits I used the silver solder that Radio Shack sold. This did require a higher temperature and I did burn a capacitor attempting to solder it in a tight spot. But, ole Doc Bottlehead replaced it for free. I would ask the Doc what solder he recommends for his kits. 63/37 or 60/40 Kiester would work fine.

The Bottlehead Forum is full of people who have built the kits and will give lots of advice and information on any of the kits. They will also help you troubleshoot any problems you may have while building or testing out the kits. The manuals I got gives you step by step instructions with pictures. I think he gives a CD with the manuals now.They also give you testing steps (usually ohmic values first, then voltages without tubes installed and then when installed). Just be careful when measuring the voltages. I would not hesitate recommending the new kits based on my experience with the older kits. But, sign up on the Bottlehead Forum and ask questions. Call the Doc and ask questions.

Whatever kit you decide to get, when it is done and working, then its a great feeling of accomplishment.

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Regarding difficulty in soldering on some pc boards, terminals, etc., it is usually due to residues which were not removed during manufacturing. The simple and effective solution is to use a tiny amount of one of the Kester no-clean flux offerings which are available from most electronics suppliers. This type of formulation does not have to be removed after soldering and makes for a really nice super-shiny, and very electrically sound connection. We used this at the industrial power supply company on all pc board connections to ensure proper electrical contact.

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My suggestion on the Radio Shack boards was for practice. In other words, solder a bit before you go to work on a $700 kit.

I did not know that there boards weren't very good.

If you've got something electronic that's busted and gathering moss , dig it out and if it's got a board practice with that. There's also various soldering videos on Utube, so you can view them also.

Once it's done and broken in, shoot me an email. I'll send you some 45's and 12AT7's to play with so you can see if tube rolling will better those Svetlanas.

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The simple and effective solution is to use a tiny amount of one of the Kester no-clean flux offerings which are available from most electronics suppliers. This type of formulation does not have to be removed after soldering and makes for a really nice super-shiny, and very electrically sound connection.

[Y]

These are all great ideas! Thebes, I hope you didn't think I'm beating up on you... I am sure that Maynard is right, and it's mostly the residue from manufacturing. That can be dealt with and you can still practice.

Dee, if you build it and like it, I am really interested in how you feel it compares to the Wrights, etc. There are so many good 2A3 amps out there.

Bruce

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Is this a great forum or what!

Thanks all for your support and advisement. I've ordered the Stereomour kit with the output impedance switching option. On the website Bottlehead is recommending or order by the end of October for Christmas delivery. That will give some breathing room to get a space organized and do some practice soldering.

Duder- thanks for the offer of sending some parts for practice. You've got a PM

Thebes - thanks for the offer on 45 and 12AT7 tubes for checking out. I've been curious about the sound of 45 tubes for years.

Marvel - I will be glad to share my take on Wrights vs Bottleheads.

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Of course not Marvel. Seriously, I did not know that and it's good to know. The important point was practice. Wish I had done some of that before plunging into a rebuild with oodles and oodles of help from my good friend and tutor, MIkebsa2A3

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