13D5 Brimar tube

[Happy Ghost]

Hello,

It looks like a 13D5 tube is a drop-in replacement for the 12Au7 in the C2A (and also the Crack).. Can someone let me know otherwise. I am planning to pop in a 13D5 in my C2A ...

Also does anyone know of a good 6CG7 to 12Au7 adapter?

Thanks!

[Larpy]

I don't have a Crackatwoa, but I used 13D5 tubes in lieu of the 12AU7s in my Foreplay III without any issues, so it should work.

The best adapters I've seen are made by garage1217.com, but it doesn't look like they have a 6CG7 to 12AU7.  They do have a 12AU7 to 6SN7 adapter though.  $25 each, so they're not cheap, but they're beautifully made.

[Happy Ghost]

Thanks Larpy.. I do have the adapters for 6SN7 to 12AU7.. I was using a RCA 5692 in my C2A for the longest time (absolutely love that tube).. all the adapters that I tried introduce a small hiss when the volume is cranked to the -9DB level but it's nothing serious..

 Just want to try a few diff tubes now..  13D5 seems like a drop-in replacement.. But I have also heard great things about the 6CG7/6FQ7.. Maybe I will buy a Crack next time it goes on sale and rewire it so that it uses 6CG7/6FQ7..

Let's hope the crew at BH introduce a successor to the C2A.. that would be spectacular

[Larpy]

At least with the Foreplay III, I could never find a 12AU7 or an equivalent that I liked the sound of.  I tried most of the usual recommended NOS 12AU7s, 6189s, 5814s, 5963s, and the Brimar 13D5s.  Eventually I rewired my FPIII to use 6SN7s and the sound improved significantly, at least to my ears.

So if you have a 6SN7>12AU7 adapter and have a good pair of 6SN7s, I'd stick to that.  If you're really keen on trying the 6CG7s, you could rewire the 12AU7 sockets.  They're not that different, and it's a straightforward mod.  Here's a thread on how to do it:  https://forum.bottlehead.com/index.php?topic=11457.0

[Larpy]

Let's hope the crew at BH introduce a successor to the C2A.. that would be spectacular

I doubt that's in the cards.  From what I've read on the forum, Doc and Eileen are eyeing retirement and have simplified the product line to make their lives easier.  Apparently, the three-tier strategy (offering entry-level, mid-level, and premium versions of the same piece of BH gear) didn't work out so well: customers gravitate to either the cheapest or no-holds-barred kits.  In between products like the Crackatwoa just didn't sell as well.

I always wanted to build a Crackatwoa but it was discontinued before I got around to ordering one.  I built a Mainline years ago and decided it wasn't for me, so I sold it.  Since my main headphones are Sennheiser HD800s, a souped-up Crack (which is what the Crackatwoa is, or was) would probably make me very happy.  But I'm content listening through my S3X.  And I have another homebrew headphone amp that sounds very good, so I'm pretty well covered.

[Happy Ghost]

In between products like the Crackatwoa just didn't sell as well.

Yeah.. and to my mind, that is a real tragedy.. The C2A is truly spectacular... 

I always wanted to build a Crackatwoa but it was discontinued before I got around to ordering one.  I built a Mainline years ago and decided it wasn't for me, so I sold it.  Since my main headphones are Sennheiser HD800s, a souped-up Crack (which is what the Crackatwoa is, or was) would probably make me very happy

So I have the Mainline around too. .For low impedance phones, it is amazing... But  much like your experience, with cans like the 800S I use the C2A.. I think the Mainline appeals to your mind, while the C2A tugs at your heart.. At least that's how I feel

[Happy Ghost]

At least with the Foreplay III, I could never find a 12AU7 or an equivalent that I liked the sound of.  I tried most of the usual recommended NOS 12AU7s, 6189s, 5814s, 5963s, and the Brimar 13D5s.  Eventually I rewired my FPIII to use 6SN7s and the sound improved significantly, at least to my ears.

For my listening tastes I was surprised to see how much  the Brimar 13D5 rocks with the C2A.. I am really enjoying the tube.. Not as holographic as a RCA 5692 but it is more accurate and musical..  It is pretty quiet too.. Definitely worth checking out.. Doesnt cost an arm and leg compared to some other NOS tubes