S.E.X. 2.0 iron upgrade kit now available

[Doc B.]

Sorry this took so long, folks. We had the manual complete, but got caught up with a long wait for iron-

http://www.bottlehead.com/store.php/products/iron-upgrade-kit-for-sex-kit-20

[fullheadofnothing]

I know people will be curious if this upgrade is compatible with the impedance switching kit. Unfortunately it is not, due to wiring differences between the S.E.X. 2.0 and 2.1.

[Paul Birkeland]

With a little ingenuity, these could work quite nicely in the old Paramour I/II if you have the Speco output transformers (in my opinion at least).

-PB

[John EH]

Aaarrggghhhh.  You would do this today.  I was about to buy the Crack and now this.  Now I have to make a decision.

[John EH]

And you forced me to make a decision.  If you check your pending orders you'll see I got the Crack w/ Speedball Update.

New iron has to wait.

Blast you Bottleheads and your cool stuff.

[Doc B.]

Thanks John!

[Jim R.]

PB -- great minds think alike :-)  I bought one set of this iron for my s.e.x. 2.0 but another will be on the way in the future -- to pair with my second pair of pt2s.  Now I just have to find some plate chokes for a 300b amp and I could have a set of monoblocks for 45s, 2a3 and 300b.

-- Jim

[Natural Sound]

With a little ingenuity, these could work quite nicely in the old Paramour I/II if you have the Speco output transformers (in my opinion at least).

-PB

I'm very interested. I know this iron is the same as in the Stereomour's so I had the same idea. I don

[galyons]

With a little ingenuity, these could work quite nicely in the old Paramour I/II if you have the Speco output transformers (in my opinion at least).

-PB

I'm very interested. I know this iron is the same as in the Stereomour's so I had the same idea. I don

[Paul Birkeland]

1. Is it safe to assume that a Paramour II could use this iron in the 45 configuration?

Yes, use the plate choke connections advised in the SEX upgrade instructions that come with the kit for the 45.

2. Would it be advantageous to reuse the Triad CX7 choke in the power supply like in the original Paramour II iron upgrade? (CRC to CLC)

Absolutely a great idea.

3. Would the parafeed cap value need to change?

I don't even remember what the original value was, lol, but I think you could try anything in the neighborhood of 1uF to 4.7uF.

 
4. Would the cathode resistor need to be optimized for the new iron?

I don't believe so, as the original Paramour used 4K output transformers.

5. This one might sound a little stupid but... The kit includes two output transformers and two plate chokes, right? I assume that the picture is only showing one channel.

Yes, the price is for a pair of iron.

To ratio the output transformers to 4K, just adjust the secondaries (run your 8 Ohm speakers on the 16 Ohm configuration).  The impedance switching kit could make the experimentation pretty fun. 

-PB

[Natural Sound]

Thanks PB. I ordered up a set last night. BTW, the original value for the parafeed cap was 3.3uF 630v. The Paramour upgrade kit with the BH5/BH6 MQ iron changed the value to 10uF.

[Paul Joppa]

For the 45 the choke will use the 40 henry/35mA taps, so the nominal cap is 5uF. It was higher with the old MQ iron because that was a lower 3K impedance transformer.

Aside #1 - you would calculate a 1.25uF for the 10-H choke of the original, but that gives a rolloff around 45Hz, so I spec'd 3.3uF back then to extend the bass, at the price of less deep bass headroom - ending up with 3.3uF.

Aside #2 - In the Stereomour 2A3 using the 20H/50mA taps, the calculated values is 2.5uF, so we still ship 3.3uF as being close enough for either 2A3 or 45.

[Natural Sound]

For the 45 the choke will use the 40 henry/35mA taps, so the nominal cap is 5uF.

Argh, I wish I knew that before I placed my [wrong] cap order.

[Paul Joppa]

As always a range form half to twice the nominal are all pretty good. That's 2.5 to 10uF. With the new choke, the differences are i the 12Hz range - not a big problem area!

[Natural Sound]

Can someone tell me if the new iron uses #6 or #8 hardware? Also what is a good source for fiber shoulder washers and solder tabs? -Thanks.