Photo Gallery -- Simple SE build

[rkevans]

I started building a tubelab.com Simple (space) SE amp this weekend and took a couple photos.

Album here: http://picasaweb.google.com/rkevans....ETubeAmplifier

Rick

[Ty_Bower]

Nice photo journal. I love when people document their builds. You've done a nice job with the build, and the pictures are good too.

I hate to be the one to break the bad news, but your 5AR4 is dead. It has air in it. The getter flash has turned all white. Don't try to power up the amp until you replace that tube.

[HollowState]

What Ty said. He beat me to it.

Victor

[rkevans]

Well, naturally my 5AR4 is dead. I have (almost) enough parts to build two complete amp boards, including a second PCB.

Two drivers, two pair of output tubes.

But only one 5AR4. "It should outlast the other tubes." Wrong. It was VERY tight-fitting when I put it in the socket. I tried a few times, and everything lines up, so I just sorta pushed a bit harder and it finally fell into place.

What the photos don't show is a small crack by the base... Time to order a new one (and a spare this time).

Whoops.

Rick

[Ty_Bower]

Don't throw the dead 5AR4 in the trash.

Wrap it in duct tape, and keep it around to "break-in" virgin tube sockets. It'll reduce the likelihood of having this problem again in the future.

The duct tape is just to keep broken glass shards away from the palm of your hand.

[rkevans]

Ty,

I like the duct tape idea. I was going to keep the dead tube either way, just as a reminder and for 'show and tell'.

A replacement pair of rectifier tubes (Another JJ and a Sovtek spare) should ship from AES tomorrow. The only 'big' item left on my shopping list is a pair of Edcor OPTs. Then I need to start thinking seriously about designing an enclosure.

Rick

[Nanook]

a tube assisted STI is too cool.

Would help in the northern climes to pre-heat the intake air (-40 ℃ is a little too cold....)

[Ty_Bower]

Originally posted by rkevans
The only 'big' item left on my shopping list is a pair of Edcor OPTs.

What made you go with the Edcor? Are you using the CXSE, or the less expensive XSE? Which other OPT did your consider?

[rkevans]

Originally posted by Ty_Bower


What made you go with the Edcor? Are you using the CXSE, or the less expensive XSE? Which other OPT did your consider?

If I had to buy something in the next 10 minutes, it would be:
The 'surprisingly good value' XSE15 for $20 each.

I've also considered:

The GXSE 'slight upgrade for $10 more' from Edcor.
The CXSE 'bigger upgrade for 4x the price' from Edcor.

The Hammond 1628 'safe choice, and pretty good iron' for $100ish each. I'm using the Allied power tranny and a Hammond filter choke, so this would really complete the set.

The 'economy Transcendar' on Ebay for $112 per pair (w/ shipping). Lack of a 40% tap and limited reviews eliminated this one. George seems very pleased with his Transcendar OPTs, but he has the 'no longer available' version from a few years ago.

The UBT-2 from One Electron at $110 each. Haven't seen many reviews/mentions of these, but the ones I've seen have been uniformly positive.

At some point, I became overwhelmed by the options and couldn't make a choice. I can't apply power to the project for initial testing until I buy something. So I've decided to go with the 'it will work, it's cheap, stop looking' solution.

I expect to replace them later with something nice, and these can be recycled into a second project.

But for now, I'm more concerned with applying power to the amp and finally being able to listen to my exhaustive collection of polka songs on 8-track.

Rick

P.S. I'm kidding about the polka. It's all disco.

[Ty_Bower]

Originally posted by rkevans
The 'economy Transcendar' on Ebay for $112 per pair (w/ shipping). Lack of a 40% tap and limited reviews eliminated this one. George seems very pleased with his Transcendar OPTs, but he has the 'no longer available' version from a few years ago.

Gery (the eBay seller) will add a 50% UL tap to the Transcendars for a very reasonable fee. Just send him an email before you buy a set. The only downside is that he doesn't stock the tapped version, so it adds a couple weeks to his shipment time.