[poseidonsvoice]

Ed,

You go, you go, you go!

Bottlehead is what got me into this DIY craze and my first build was a Foreplay Mk 1.0. I still have it (somewhere  ) and I saved those 12AU7 tubes which were Amperex PQ types!

Good luck with your build, you'll have great sonics to boot, Dan Schmalle and Paul Joppa are class acts!

Anand.

[ebag4]

Ed,

You go, you go, you go!

Bottlehead is what got me into this DIY craze and my first build was a Foreplay Mk 1.0. I still have it (somewhere  ) and I saved those 12AU7 tubes which were Amperex PQ types!

Good luck with your build, you'll have great sonics to boot, Dan Schmalle and Paul Joppa are class acts!

Anand.

Thanks Anand.  I also built a Foreplay (II) about a hundred years ago.


The wiring is now complete minus the hum pots which I believe are back-ordered.  Next up the base.  The kit is basically stock.  I have used Azuma tube sockets instead of the stock units, since I did not use a volume control I have added a 100K resistor across each input, and I used a couple of 2.2 uF Obbligato caps I had instead of the stock 3.3 uF Solens that came with the kit.

Best,
Ed

[TomS]

Wow, very neat and tidy job I'm really enjoying this thread. Please do keep them coming... Should be great on the coax's.

[JohnR]

Ha, has anybody not built a Foreplay?

Nice work - what's the small board? CCS?

[ebag4]

Thanks guys. 

It was nice having a free weekend, it allowed me to put some time toward completng this amp.  Free weekends are a rarity when you have a high school wrestler in the house.

Yes John, the small board is the CCS.

Best,
Ed

[ebag4]

Time for a quick update. 

The base is started, it still needs lots of sanding and the legs are not glued but this will give an idea of what it will look like. 

I had another design but when I mocked it up I didn't like the look as much as I did when I drew it up, it would have added a couple inches front to back and side to side, I didn't want to make it that much larger.

I haven't started the cover for the transformers but that can wait until the end.

My hum pots are in transit so I hope to be able to listen to the unit in the next day or so.

Best,
Ed

[eclein]

Awesome!!!!

[ebag4]

Hum pots arrived and are now installed!!  I will be listening to my amp tonight assuming all of the resistance and voltage checks are within spec.





Best,
Ed 

[jtwrace]

Ed

That's amazing that you've got it done already.  WOW!!!!  Let us know what you think of it when you fire it up. 

   Ron builds GR speakers and you can build Bottleheads....

[jparkhur]

I see a new company forming......

[JakeJ]

Very nice work, Ed!  Excellent wiring work, and that chassis/cabinet is going to be stunning.  Have you mentioned what your plans are for the final finish?  Satin, high gloss, oiled & natural?

Man, that's going to look as good as it sounds!

[ebag4]

Well guys, I couldn't wait.  I completed the resistance and voltage checks, all but a 230VAC reading were right on, the 230VAC reading was low on all 4 spots it occurs so I called Dan (Doc Bottlehead) and ran the issue by him.  He said it should be fine and that they are seeing this here and there and believe it is attributable to differences in the 12AT7 tube. 

My cheap meter wouldn't read AC millivolts so with no music playing I adjusted the hum pots by ear, each was able to get the hum to all but inaudible with my ear in the speaker cone, so far so good!  So I fired up MPD and VIOLA, music!!! 

When the music started playing something I really didnt expect occured, bass in abundance.  Now the bass section of my speakers is handled with a servo amp per speaker so the bass (or mid bass) I am talking about is coming from the coaxials.  This is a surprise to me becasue I felt the amp I was using before had excellent bass coming from the coaxials (200 Hz and up).

Edit* Duhh , the additional bass isn't coming from the coaxials, I just had to adjust down the output of the servo amps to work with the bottlehead amp.  With the lower output of the 2a3 the volume out of the coax was lower than with other amps so the output of the servos was accentuated.

Anyway, this is all very early, the amp hasn't even warmed up yet, but so far I am a very happy customer.

Great work Doc, Eileen, and Paul Joppa  .

More to follow as I put some time on the amp and get the base built.

Best,
Ed

[ebag4]

Ed

That's amazing that you've got it done already.  WOW!!!!  Let us know what you think of it when you fire it up. 

   Ron builds GR speakers and you can build Bottleheads....

Very nice work, Ed!  Excellent wiring work, and that chassis/cabinet is going to be stunning.  Have you mentioned what your plans are for the final finish?  Satin, high gloss, oiled & natural?

Man, that's going to look as good as it sounds!

Thanks guys, it really is a nice piece of kit, the instructions are outstanding and I was able to get the little bit of tech support I needed concerning the voltage readings with a very quick phone call.  All in all a great experience.

Jake, I will probably use the same finish  used on the V1s which was multiple coast of gloss with a final coat of semi gloss.

Best,
Ed

[TomS]

Don't you love it when a plan comes together! I'm sure it sounds great already and it looked like a lot of fun to build.

[richidoo]

Congrats Ed! Nice build thread, thanks!

[jtwrace]

Well, how does it sound?

[Ericus Rex]

Yes, very nice and super clean work!  I bet she sounds awesome!

Did you mortice the wood sides into the pillars?!?!  Wow!

[eclein]

Way to go Ed, you give all the Ed's in this hobby hope....LOL....
 Thanks Ed!!!
 I feel rather small now -Ed

[ebag4]

Don't you love it when a plan comes together! I'm sure it sounds great already and it looked like a lot of fun to build.

Yes I do Tom.  It was an easy build but still a very nice product.

Congrats Ed! Nice build thread, thanks!

Thanks Rich, most of the filks on AC seem to enjoy build threads so I am happy to add my small offering.

Well, how does it sound?

Well Jason, so far it sounds quite diferent from what I was using.  It doesn't make any sense to me yet but for some reason the bass has changed, yes, the bass that is handled by the to servo amps.  I can't imagine why unless it has something to do with how the amps are loading the Dodd Buffer.  Initially the bass was different because it was simply at a different level due to the 2a3 powering the coaxes differently, but once I staightened that out the bass seems to have more texture but this amp doesn't play with those bass drivers.

The sound through the coaxials is presentled differently, perhaps a litlle darker, but I only have a couple of hours on the amp so I will wait until the unit has had more time to settle in before doing any critical listening.

Yes, very nice and super clean work!  I bet she sounds awesome!

Did you mortice the wood sides into the pillars?!?!  Wow!

Hi Eric, I was wondering how long it would take for someone to ask how th pillars are connected  .  No, they are not mortised, I don't have the tools to do that.  Instead I used the tools I do have, in this case a table saw.  Since I didn't have any way to cut a corner into the pillars I simply notched them straight across and then cut the corners off of the frame at 45 degree angles, this allows the notched pillars to fit over a flat face on the corners of the frame if that makes sense.

Way to go Ed, you give all the Ed's in this hobby hope....LOL....
 Thanks Ed!!!
 I feel rather small now -Ed

Hey Ed, there is always hope!  What's the worst that could happen, it doesn't work right off the bat and you have to bounce questions off this or Bottlehead's excellent communities until you get it to work, that doesn't sound so bad, does it?

BTW, guys, I believe I overstated/understated the amount of hum.  In checking it again this morning, I can hear a slight hum with my ear in the coaxials, but once my ear is out of the drivers I can no longer hear it.  I am a bit sensitive to hum and as of now I would have to say it doesn't bother me in the least.

Best,
Ed

[Pez]

Your bass experience is very common. Both Tyson and I hear substantial changes in bass response when messing with amps. For one bass experience is often influenced by the relative gain level of the bass amp to the mid and treble amps. Two there is a lot that one attributes to 'tight bass' or other characteristics that have more to do with the voicing of the mid and treble amps.
Crazy huh?