[carlman14]

Something like this

Hey, that's a screenshot of my previous BHC! It's a triad c-7x. You can get them from mouser.com. Though any choke will do, as long as it can handle roughly 90-100mA and has a DC resistance roughly the same as the resistors in the BHC PSU (270 ohms).

 

[ShizzyGuo]

Listening to Anchor by Novo Amor with my KISS modded HD6xx's and non speedball Crack with Mullard 6080 and Ken Rad VT-231. Absolutely amazing.

 

[pravous]

Hey, that's a screenshot of my previous BHC! It's a triad c-7x. You can get them from mouser.com. Though any choke will do, as long as it can handle roughly 90-100mA and has a DC resistance roughly the same as the resistors in the BHC PSU (270 ohms).

Which resistor did you replace with the choke? The one on the left by the iec inlet or the the one over the transformer?

 

[carlman14]

Which resistor did you replace with the choke? The one on the left by the iec inlet or the the one over the transformer?

The one over the transformer (the "first" R in the crack's CRCRC). After replaced, it's a CLCRC PSU. If there is one mod everyone should do, this is the one (well, and film output caps too). It made the biggest difference by far in the amp. It makes the background noise of the crack much much quieter.

 

[JamieMcC]

There is pretty much a step by step guide to installing the choke in the power supply on the Bottlehead forum lots of pics from folk who have done the mod and some modeling of power supply ripple with the choke.

From memory as a result of using the choke I seem to recall the last electrolytic capacitor in the power supply can be replaced with a much smaller value down from 200uf to something like 50uf so you can get away with using a low esr film capacitor in its place of the elecrolytic capacitor. Anyhow the guide has all the info you require.

 

[JiggaD369]

Has anyone here done a 4-pin XLR for the headphone output?

 

[dstarr3]

Has anyone here done a 4-pin XLR for the headphone output?

You can do that, but that wouldn't make the amplifier actually balanced. You would just send the single shared ground to the two negative pins.

If you want to connect 4-pin XLR headphones to a BHC, it would be a lot easier to make a 4-pin XLR to 1/4" male adapter.

 

[JiggaD369]

You can do that, but that wouldn't make the amplifier actually balanced. You would just send the single shared ground to the two negative pins.

If you want to connect 4-pin XLR headphones to a BHC, it would be a lot easier to make a 4-pin XLR to 1/4" male adapter.

Ya not trying to make the amp balanced, but my HP connections will be 4-pin XLR.

The part I'm trying to figure out is how to wire the 2.5k resistors on the jack itself.

 

[LCMusicLover]

Modded BHC/Speedball here, runs dual 6J5 for input (or a std 12AU7).

Anyway, right now, running Chatham 5998 and GEC 6L3 pair. I suspect these might be end-game tubes for this amp. Nothing else I’ve tried beats that power tube, including a WE 421A & a bunch of different 6080s.

6L3 seem to max the airy stage. I’ve tried some good 5814 & 4003 input tubes — not bad but prefer the 6L3s. Also vs some 6J5G/GTs I’ve tried.

But I’m always interested in other opinions …

 

[dstarr3]

Modded BHC/Speedball here, runs dual 6J5 for input (or a std 12AU7).

Anyway, right now, running Chatham 5998 and GEC 6L3 pair. I suspect these might be end-game tubes for this amp. Nothing else I’ve tried beats that power tube, including a WE 421A & a bunch of different 6080s.

6L3 seem to max the airy stage. I’ve tried some good 5814 & 4003 input tubes — not bad but prefer the 6L3s. Also vs some 6J5G/GTs I’ve tried.

But I’m always interested in other opinions …

Lordy, it's the BHC of Theseus

 

[jonathan c]

“Colossus of Crack” …..

 

[RestoredSparda]

Hi all. I have a set of 4 NOS 6C45pi Sovtek tubes available that I never used with my Mainline. PM me if you want them for cheap.

 

[JiggaD369]

My tube folks!

How is this for test results for NOS? (I know nothing about tube tests).

 

[DenverW]

My tube folks!

How is this for test results for NOS? (I know nothing about tube tests).

Honestly, you can’t really tell. On the surface it looks good, right? But without knowing what he used to test them, what settings, and the specs for the tube for that tester it’s just…an idea.

For example, what is the ‘minimum good’ number he’s using? Is anything under that considered a dead tube? Is the tube at 100% life with those readings or 50%, but over the minimum good? See what I mean?

Finally, consider the source. If this is from eBay there is a possibility that the numbers could be fabricated.

 

[JiggaD369]

Honestly, you can’t really tell. On the surface it looks good, right? But without knowing what he used to test them, what settings, and the specs for the tube for that tester it’s just…an idea.

For example, what is the ‘minimum good’ number he’s using? Is anything under that considered a dead tube? Is the tube at 100% life with those readings or 50%, but over the minimum good? See what I mean?

Finally, consider the source. If this is from eBay there is a possibility that the numbers could be fabricated.

these are the pics I was sent

Honestly, you can’t really tell. On the surface it looks good, right? But without knowing what he used to test them, what settings, and the specs for the tube for that tester it’s just…an idea.

For example, what is the ‘minimum good’ number he’s using? Is anything under that considered a dead tube? Is the tube at 100% life with those readings or 50%, but over the minimum good? See what I mean?

Finally, consider the source. If this is from eBay there is a possibility that the numbers could be fabricated.

This are the test pics I was sent