Bottlehead Forum

Bottlehead Kits => Eros Phono => Topic started by: shelby1420 on April 08, 2011, 01:58:25 PM

Title: Couple of Questions re the Eros
Post by: shelby1420 on April 08, 2011, 01:58:25 PM
Hey all, just did our taxes and this year is a good one:)  this translates into me getting to buy a Eros, yippee!!!!  Couple of questions, from my understanding the there is only one signal cap per channel, what is the value of this cap??  I see there are 2x - EF86 - 1x 6DJ8 - 1x 12BH7, 6DJ8-7308-6922 i have enough to open my own little store so covered well there but what about the other tubes, I figure the EF86 are mucho important and if I have extra funds to soak em on the EF86 before the 12bh7-- does this make sense??
Title: Re: Couple of Questions re the Eros
Post by: Grainger49 on April 08, 2011, 02:30:00 PM
The only signal path cap is the output stage which is configured like a Seduction using the 6922.  That is to say you can use a 0.47uF 600V cap there with no loss in bass response.  The kit comes with a 1.0uF 600V as an upgrade.

The EF86 is most important. It is first and that is where most of the gain comes from (and it is where low noise is most important).  I'm a big fan of Russian Military Surplus parts like their Teflon Caps.  There is a Russian equivalent the 6J32P tube.  Old stock from the 60s and 70s are said to be the best.  For the 6922 the Russian equivalent is the 6N23P.

The 12BH7 is the voltage regulator.  I think Doc has posted that it can make a difference but memory isn't clear.  The greatest effect comes from the first tube the EF86.
Title: Re: Couple of Questions re the Eros
Post by: Paully on April 08, 2011, 02:57:44 PM
http://www.bottlehead.com/smf/index.php/topic,1386.0.html

You might want to read through this thread as well.
Title: Re: Couple of Questions re the Eros
Post by: Paul Joppa on April 08, 2011, 04:59:27 PM
The 6H23 is a 6922 equivalent, a bit better specs but nothing significant in the Eros circuit.

The EF86 is the difficult one. The best of them - mostly old-stock European versions - are getting very rare and expensive. That means most of what's on the market has been rejected by the more careful users and retailers, usually for noise reasons. The modern-production ones that Bottlehead ships has been fairly quiet, but we had to implement the servo bias in Eros to get it to bias up properly.

DocB knows more about these, from the Tape Project work. Hopefully he'll post something.
Title: Re: Couple of Questions re the Eros
Post by: shelby1420 on April 09, 2011, 02:17:18 AM
Ya, I see they are becoming scarce/expensive......... looking at a few selections from some of the more reputable dealers, I may order them now just to make sure they are gone, thinking the cheapest I am gonna get away with is about 200.00 for a pair!!!
Title: Re: Couple of Questions re the Eros
Post by: debk on April 09, 2011, 05:51:32 AM
I am running my Eros with a pair of NOS Genalex Z729's, they sound very sweet.
The other tubes in the Eros are a NOS RCA 12BH7, and I know this is overkill, but I had a single Siemens Halske CCa.


Debra
Title: Re: Couple of Questions re the Eros
Post by: shelby1420 on April 09, 2011, 07:34:56 AM
Hey Debra, i was thinking of those or the Amperex Bugle Boys......
Title: Re: Pinging Doc or Eileen.....
Post by: shelby1420 on April 09, 2011, 07:47:04 AM
Hey guys, check your emails, thanks all!!
Title: Re: Couple of Questions re the Eros
Post by: debk on April 09, 2011, 07:56:12 AM
Hey Debra, i was thinking of those or the Amperex Bugle Boys......

I had a pair of Amperex Bugle boy in it before the Z729's.  I also tried a pair of  Telefunken EF806s.  In my system I like the sound of the  Z729's the best

Debra
Title: Re: Couple of Questions re the Eros
Post by: tttubes on April 13, 2011, 02:38:53 AM
Just was looking on eBay there's lots of ef86's at good prices.

These are my current favorite

 http://cgi.ebay.com/Philips-E80F-6267-EF86-Stereo-Tube-SQ-Gold-Pin-Lot-2-/250670749115?pt=Vintage_Electronics_R2&hash=item3a5d2415bb
Title: Re: Couple of Questions re the Eros
Post by: Paully on April 13, 2011, 03:19:03 AM
And when I look at Upscale Audio and other reputable places there are options for under $100 a pair.  And don't forget the Russian equivalents from the 60s which are a really, really good option as someone mentioned.
Title: Re: Couple of Questions re the Eros
Post by: debk on April 13, 2011, 08:05:16 AM
I just got a quad of the Russian versions, have not tried them yet

Debra
Title: Re: Couple of Questions re the Eros
Post by: levlhed on July 29, 2011, 08:59:52 AM
interested in hearing what you hear
Title: Re: Couple of Questions re the Eros
Post by: grufti on December 25, 2011, 05:01:19 PM
That tube is almost never overkill. It is the exact tube that I ended up with in my Eros build. Now I'm torn between moving it to a new amp or trying to buy a few more.

Merry Christmas
Hans

I am running my Eros with a pair of NOS Genalex Z729's, they sound very sweet.
The other tubes in the Eros are a NOS RCA 12BH7, and I know this is overkill, but I had a single Siemens Halske CCa.


Debra