Bottlehead Forum
Bottlehead Kits => Moreplay => Topic started by: timmieec on March 25, 2024, 05:49:47 PM
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From sunny Singapore, hello everyone!
Starting a log for my Moreplay build, my first Bottlehead kit!
I stained the wood base using Super Black India Ink. Have yet to top coat using spray on lacquer.
For the bell and chassis, after masking the back side, I spray painted with high heat primer first, then aluminium colored engine enamel and finally clear engine enamel. I chose these products because I wasn’t sure how much heat the tubes and transformer would generate and if normal spray paint would’ve worked or not.
I’m pretty happy with the color combination!
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Regular spray paint usually works fine, but using the high heat paint certainly doesn't hurt. And it looks very nice! A tip for your wood base - a coat of shellac on the wood before you apply lacquer helps fill the grain,
with fewer coats of lacquer needed. I learned that trick from an old timer when I was restoring antique radios. Just go easy when you sand the dry shellac before putting on the lacquer. If you get too heavy handed the shellac can get soft and gummy on your sandpaper.
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Thanks Doc!
Will definitely consider it. Not sure I’d be able to apply the shellac without creating brush strokes and an uneven surface but will look to maybe practice on some other wood scrap first.
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Yeah, you have to lightly sand brushed on shellac to get it smooth before spraying lacquer. You can also use spray shellac. It will take several coats to build up enough to fill the grain. And yes, skipping the shellac and just applying a whole lot of coats of lacquer will work too. There are many different ways to do a lacquer finish. I've even used clear epoxy scraped smooth with a razor blade while still soft to fill the grain in mahogany before applying a finish coat.
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Not sure I’d be able to apply the shellac without creating brush strokes and an uneven surface but will look to maybe practice on some other wood scrap first.
I am a big fan of shellac for a varnish type finish. I'm using it on my new Moreplay and StereoMour bases from a spray can. Zinsser sells it. Premixed shellac has a shelf-life of about 2 years, and when old will no longer dry hard.
It's very easy to use. I am sanding using 400 grit on an orbital sander between coats. Coats are very thin, just 1-2 spray passes. If you wanted a satin finish the 400g sanded finish is excellent. And 3-4 coats will get to complete coverage in just an hour or two. Coats can be sand in about 15 minutes in warm dry conditions (slower if cold or humid).
Shellac is actually quite durable. It's very durable against most wear and water, although can be damaged by water if left in contact for a long time, and alcohol dissolves it. It melts at about 70C (160F), which I think may account for the gumminess caused by overly vigorous sanding.
It was what was used for almost all "varnish" finishing for centuries, including floors, until lacquer and other modern finishes were invented. It's probably the easiest varnish type finish to apply. Unlike virtually all other varnishes, it can very easily be repaired simply by light sanding and recoating. The dried finish is completely nontoxic, and is in fact used on food, for example, apples are shellacked to extend shelf life.
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If you are concerned about brush marks when applying shellac you can use a pseudo French polish method and forget the rotten stone. It will go on very smooth and dry quickly, but it will take a lot of applications to fill the grain of the wood. then you can leave it that way or apply a real cellulose lacquer or simply apply furniture wax, Lacquer made for musical instruments is best but it is very irritating. but it looks beautiful.
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Lacquer is OK over French polish? Good to know. I wouldn't have thought so because of the oil.
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Timothy,
Looks like you are off to a good start, keep up the good work.
Karl
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Beautiful!
I used just wax on mine (briwax).
keep us posted and thanks for sharing.
Cheers from Fla.
Andre.
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Thanks everyone for the suggestions!
The Zinsser shellac spray is "currently unavailable" on Amazon Singapore :( DIY in Singapore is really not as fun as in the US...
I've mounted all the components onto the chassis plate but am not sure if I've put the 4-pole 3-position rotary switch in the right place. The instruction manual says to mount it in the hole in the front left corner but in the accompanying photo it looks like it's mounted in the hole towards the side with the RCA jacks, which is the hole in the front right corner. I decided to follow the photo and so I placed it in the front right corner hole (refer to second photo). Is this correct?
I have annotated the underside of the chassis plate as the manual suggested and love how much it should reduce the chances of erroneously connecting stuff :)
Once someone's confirmed I've mounted the 4-pole 3-position rotary switch in the right place I'll move on to the hard part, soldering!
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You are all set, good luck. Take your time and enjoy.
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Your selector is correctly mounted.
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Thanks for catching that typo!
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I dont think is a typo. left or right will variate regarding if the plate is up side down or vise versa. For intalation the plate should be upside down thus the selector is on the front left.
Its great the instructions are so well ilustrated that clarify any question.
AG.
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Thank you everyone for the confirmation!
Yes true that it is in the front left corner when viewing the underside of the plate. Perhaps a good way to phrase it would be something like “the slotted hole furthest away from the power switch”? Because then it’s viewing angle agnostic :)
It’s a 3 day weekend in Singapore so I’m hoping to make decent progress! I’ll go slow because as the manual says, there’s no prize for fastest build ;D
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Hi,
There is plenty of wire in the kit, I will recommend to cut them 7 to 10 mm" longer than the instruction require.
longer wire could be acomodated, shorter ones are a pain.
Cheers from Fla.
Andre.
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I’ll go slow because as the manual says, there’s no prize for fastest build ;D
Yes, this is a good plan.
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Over the weekend I:
1. Measured mains voltage (245V)
2. Finished wiring up the power transformer for over 230V
3. Checked voltage across power transformer terminals 6 and 7 (9.6V, within spec of 8-10 VAC), and across terminals 9 and 10 (121.5V, within spec of 110-130 VAC)
So far so good except I accidentally cut one wire 1" too long and had to trim it off. Hopefully there's still enough wire for everything else!!
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You definitely win the award for high line voltage! I think your power supply DC voltages will come out a little bit high, but don't let that stop you.
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Indeed!
I’m hoping to eventually get a PS Audio power regenerator second hand to bring the mains going to my gear down to between 230-235V.
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You can do that with a Variable Output Transformer. Doesn't do any power conditioning, but you can dial in the desired voltage. See Pic.
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Thank you @hmbscott for the suggestion! I'll look into it.
I completed the heater wiring and confirmed that both tubes glow. Let there be light!
I also purchased a set of dials from AG ;D
I'm curious what brand of tubes I've received with the kit. Anyone here able to read Russian and can enlighten me please? :)
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Those are Russian tubes built during the Soviet era by, I believe, Reflektor. Good tubes. They came stock with my Moreplay as well. Depending on your tastes and level of curiosity, they might be all the 6V6 you need. To my ears they sound more like old U.S. 6V6s like GE, Sylvania, and RCA than they sound like 6V6s made currently in Russia, China, and the Czech Republic. (And I mean that as a compliment.)
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Thanks @Larpy for the information! That’s a pretty cool name, and also the name of an Arcade Fire album I think.
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Help! :(
I'm failing the raw B+ voltage test. I repeated the test 3 times and got the following peak VDC read outs: 331.2, 330.7, 331.1. The spec is 280 - 320V.
I've checked all the wiring for connectivity using my DMM and it seems like everything that's supposed to be connected passes the connectivity test. I've also confirmed the polarities of the caps and diodes are correct.
Could my raw B+ voltage be exceeding 320V because, as @Paul Birkeland noted, my mains voltage is so high (245VAC)?
Or is it definitely failing the test because of a workmanship error? If it's definitely workmanship, any advice on what else I should check besides polarity and connectivity?
The cap connected across terminals 23 and 21 is rated for 350V so there's low risk to that component. But I don't know whether the components being supplied by this DC voltage will be okay receiving 331V...
Any guidance would be much appreciated!
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Your line voltage is about 5% high, so you can expect your B+ to also be about 5% high, which means it will fall within a range of 295 - 335 VDC, and it does. So I don't think there's anything wrong with your wiring, it's your high line voltage. I can't say if it's OK or not.
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So-called "230v" power grids combine/compromise the older standards of 220v and 240v, but many of the older generators are still in use. For this reason, the Moreplay power transformer can be set for 220 or 240 - but not for 230. I think that gives our customers a better chance of getting close to optimum power. That means that Timmie's voltages are only 1% high. The circuit can withstand +/-10% variation without loss of performance or reliability.
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Thank you everyone for the guidance! Good to know that I don’t need to worry about loss of performance or reliability and can proceed with the build :)
Next up, audio circuit wiring!
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Audio circuit is done and connectivity tests seem to check out.
On to input wiring tomorrow!
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Nice and clean soldering! my hat off.
AG.
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The input wiring section was intense!
Managed to complete it though. All the resistance and voltage values checked out so I hooked it up to my Roksan K3 amplifier and started playing music through it :D
Thank you everyone for the guidance throughout and helping me make my first tube amp kit a success!
May I ask what the balance knob is for? In what instances, besides DJ-ing, would one use it to make one channel louder than the other? This is the first time I've had a balance control at my disposal and it's giving me anxiety because I don't know if I've balanced it perfectly equal between left and right channels :o
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Four reasons for a balance control:
1) amplifiers without feedback may vary in gain by a few dB due to varying tube parameters.
2) room acoustics may enhance one speaker's loudness over the other
3) for diagnostic purposes you may want to listen to one channel alone
4) typical volume controls can deviate from matched gain, especially at low-level settings
I'm sure there are more, these are just what comes to mind this morning.
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Good job. Turned out nice!
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Thank you everyone for the guidance! Will do my best to balance the preamp using tracks with a strong centre image :)
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Again, nice clean build and finish. I noticed that you are using directional RCA cables on the output and that one is reversed. Will the electrons be facing the wrong direction in that channel?
Enjoy the tunes.
Karl
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Hah thanks @Karl5150 for pointing that out! In my excitement to listen to the Moreplay, I didn’t realise I had the direction reversed ::)
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Received plates with labels for the knobs from Andre (username AG) and they look great!
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Match perfect with the color of your choice!
Enjoy!!
Cheers from Fla.
Andre.