BeePre- other tubes

[RPMac]

Other than the "standard 300B", I see where the 6B4 and 6A3 will work. I assume plug & play?

Are any of these possible candidates?

183/483

6A5

71A

[Doc B.]

It would be pretty difficult to plug and play a 6B4G in a four pin socket.

[vetmed]

I have to say off the top that I don't own a BeePre. However Bottlehead has chosen to work with the 300B doubtless because the tube has merits that made them persist in designing it in spite of problems that were encountered, and obviously overcome. To me a more obvious candidate would have been  the 2A3, seems to me that it would have been easier to get the necessary degree of quietness in the lower voltage tube. Will the tubes you mentioned "work"? Those with the correct basing will  possibly light up and make some sort of noise but will need enough mods done that it will no longer be fair to call it a BeePre. And obviously the 6B4 won't because it has a different base. Also consider that Bottlehead must work with current production tubes, which most of what you mention are not.

Regards
   Robert Lees

[RPMac]

It would be pretty difficult to plug and play a 6B4G in a four pin socket.

How about plug, plug & play with these?

http://www.ebay.com/itm/141010412920?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Robert, from what I've read, the 6B4 and 6A3 are essentially a 2A3 with high voltage filaments. I will definitely build completely stock to begin, but want to check out different flavors of DHT. PJ has mentioned the 6A3 and 6B4G...I think Xavier has tried both. I believe PJ's filament supply is the key, so I'm not trying anything without his blessing.

I have an all DHT Stereomour that PB built. I've been swapping between my Parabees, but keep coming back to the Stereomour (in 45 mode now). Once I get the BeePre built, I'll have an all DHT Bottlehead system. Which, I'm sure, will make me want to put DHT drivers in my ParaBee and ParaGlow.

Never ends, but ain't it fun!

[Paul Birkeland]

To me a more obvious candidate would have been  the 2A3, seems to me that it would have been easier to get the necessary degree of quietness in the lower voltage tube.

When you attempt to design a 2.5V 2.5A DC regulator, things get very expensive and very difficult in a huge hurry. 

On paper, the 6A3 should just about drop in, but some resistor adjustments may be necessary.

[vetmed]

Sorry if I sounded negative. Its just that there are a lot of ill-informed proposals for modifications around here that it irks me occasionally. Sometimes the proposals are for parts changes for kits that are newly released and haven't even been shipped yet On another topic I would be very interested to know a bit more about your all DHT amp

Regards
   Robert Lees

[johnsonad]

I've played around with a few tubes and IMHO the EML standard plate sounds best in my system to my ears.  Here is how I ranked them out.  Xavier uses the 6A3 in his and may be able to give more insite.

1. EML 300B
2. EH 300B Gold Grid
3. Russian 6C4C
4. Sovetek 6B4G
5. TJ 300B mesh plates

The Russian 6C4C is pretty nice and cheap.  You can get a converter for the 6B4G on Ebay for under $30 or PM and I could part with mine. 

[Doc B.]

Sometimes the proposals are for parts changes for kits that are newly released and haven't even been shipped yet

Hah! You think it irks you!

[RPMac]

Robert, I'm well aware of how it irks Doc for people to redesign his products before they have built and listened. I'm guilty in that this was a thought itch that I could resist scratching. Most all my Bottlehead gear are unmodified except for some cap replacements. The only modified amp is the DHT Stereomour I bought from Doc. He put it up on Special Deals and I immediately jumped on it, so most of you never saw it.

Doc and PB can tell you about the specifics far better than me, but it uses a 3B7 dual triode as the driver. I've had some issue with some of the 3B7 tubes with ringing. It may be ringing that I can't hear that makes me like this amp so much.

The thing that has really impressed me is the lack of hum while I played my different 2A3 tubes. I played with the hum pots once just to make sure the amp would actually hum. No matter which tubes I put in, the Stereomour was always quieter than my ParaBee.

If I can bring myself to do it, I need to apply some 'PJ power supply magic' to my ParaBee.

[corndog71]

Sometimes the proposals are for parts changes for kits that are newly released and haven't even been shipped yet

Hah! You think it irks you!

I could swear that years ago you were irked that people weren't experimenting enough.

[mcandmar]

I can fully understand why it irks you guys, truth is most of us were probably wearing diapers when you all started designing/building valve amps.

Though i do find it amusing how the vary mention of resistor upgrades seems to be your Kryptonite

[Doc B.]

I'm all for people experimenting with kits that are in production. Just like to see some logic to the experimentation. We spend an awful lot of time here working with customers on their mod ideas, and we try to offer suggestions as to whether or not a part will effect the change they wish to make. Sometimes people prefer to install $200 worth of parts chasing a problem when we can tell they probably have a bad solder joint or fried a part during the build. When they don't acknowledge our advice and start at the middle rather than the beginning it can be frustrating. I am not directing this at any individual, this is simply a general observation made from 20 years in the kit business.

"Redesigning" a kit that hasn't even come out yet is human nature, but I won't deny that I usually say to the guys "why is everyone else so much smarter than we are?"

[Paul Birkeland]

There seems to be a blurring of the line between tweaking and modification these days. 

Replacing caps, resistors, wire, pots, etc. is just tweaking what's already there.  Posts regarding this discussion can be pretty frustrating, as very few people have sat down and listened to many different parts in the same circuit (For good reasons - it takes a long time and can get expensive), so it becomes people just recommending whatever they decided to use on their last build.

An actual modification is more about changing how the amp operates.  One example is Xavier tweaking the BeePre to get the 6A3 to operate properly.  Another good example is when I worked with Chris to modify his Crack to run 5687's.  Link  Paul Joppa is perhaps the most prolific mentor in this regard, leading to a lot of all directly heated and shunt regulated amps, as well as some crazy creations hidden away at BHQ.  The funny thing about this is that these modifications generally cost a ton less than putting boutique parts into your amplifier, and there will absolutely be a difference.  (I'm still thinking about making a 1626 Stereomour) 

[Doc B.]

And so you can see that we all have slightly different priorities. Peebs has his hands in the product all day long and thus his perspective is slanted somewhat to what is practical from a construction standpoint and the visual aesthetic. PJ is the theoretician and his emphasis is in the direction of how all of the components interact and what is the "best" part for a given application based upon the circuit requirements. My perspective is the most hedonistic - I get to look at these things simply as tools to get the best sound possible for the money spent. Using my definition of best sound, naturally, based upon a lot of time (and money) spent trying to understand exactly what that means. Our perspectives overlap to a great degree and we rely upon each other a lot for input.

[Grainger49]

Dan,

A good perspective.

We all get pulled by what we do and find a problem.