What 300b's are you running?

debk · 23905

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Offline debk

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on: April 05, 2013, 02:26:34 PM
What 300b tubes are you running in your BeePre?

I have tried both the Gold Lion  and the Psvane 300b-t.  I like the Psvane better.  Sounds  a little more detailed than the gold lion tube.

Anyone have any other suggestions to try?  All the EML 300b seem to have a higher than standard filament current.

Deb
« Last Edit: April 06, 2013, 12:50:18 AM by debk »

Debra K

Eros 2Phono amp
BeePre2, Psvane ACME 300b
Kaiju, Linlai Elite  300b
Monamour 2a3 amps various tubes
Sota Sapphire, Pete Riggle Woody Tonearm, Kiseki Purpleheart Cartridge
Rega P6 Ania Pro cartridge
Roon Nucleus
MHDT Labs Orchid DAC
Jager speakers


Offline johnsonad

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Reply #1 on: April 05, 2013, 04:01:19 PM
EML will not work in the amp.

I'm using EH 300B gold grids. They are the only tube I have.....  This is an expensive preamp to roll tubes in.

It would be nice to find someone in SoCal with a stash of different 300B's that would be willing to spend some time with the BeePre at my place.
« Last Edit: April 05, 2013, 07:22:02 PM by johnsonad »

Aaron Johnson


Offline ditdah

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Reply #2 on: April 05, 2013, 10:26:22 PM
I thought the EML 300b's would work fine...but the EML 300b-mesh was not recommended.  Can you confirm the EML 300b's won't work?  I could have sworn that I was told the EML 300b's would be just fine for both the Paramounts and the BeePre.

Kenneth Koller


Offline debk

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Reply #3 on: April 06, 2013, 12:49:26 AM
The regular EML 300b has a filament current of 1.3A, slightly higher than the 1.25A most 300b are.  Don't know if the 1.3A is just 1.25A rounded up or the tube does draw slightly higher filament current than the standard 300b tubes.

I don't know how close the specs are for the filament power supply in the BeePre are, will the extra 50mA make a difference?

Debra

Debra K

Eros 2Phono amp
BeePre2, Psvane ACME 300b
Kaiju, Linlai Elite  300b
Monamour 2a3 amps various tubes
Sota Sapphire, Pete Riggle Woody Tonearm, Kiseki Purpleheart Cartridge
Rega P6 Ania Pro cartridge
Roon Nucleus
MHDT Labs Orchid DAC
Jager speakers


Offline ditdah

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Reply #4 on: April 06, 2013, 01:03:22 AM
Admittedly...I guess I'm talking more Paramount than BeePre...  but I'm hoping the EML 300b's are fine for either.  As for the 50mA question...I'm going to have to defer to someone more knowledgeable.

Kenneth Koller


Offline johnsonad

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Reply #5 on: April 06, 2013, 03:33:08 AM
There is a thread on it already. Unless you want to put your beePre in a fridge to keep it cool, EML tubes will not work in the BeePre (they work fine in the Paramount). They all draw too much current and with the highly regulated filament supply you will starve the tubes. You could adjust the regulator which PJ says is possible (and the transformer has the reserve) but at the cost of more heat. I asked Jac and he of course said he will not warrenty the tubes if they are not run to proper current.

We should focus on the tubes we can use safely in the BeePre and keep on Bottlehead to add this adjustablility to version 1.1. Or if someone wants to adjust their regulators and spend a good amount of change to try it, please post your results and temp readings of the BeePre. I really want to use EML myself, don't get me wrong but I also want the tubes and the preamp to have a long and happy life.
« Last Edit: April 06, 2013, 03:50:44 AM by johnsonad »

Aaron Johnson


Offline debk

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Reply #6 on: April 06, 2013, 04:10:28 AM
The other thread is mainly about the EML mesh plate 300b which has a filament current of 1.5A.  That we know will not work
Is there enough reserve for the 1.3A draw of the solid plate EML 300b in an unmodified BeePre?

Deb

Debra K

Eros 2Phono amp
BeePre2, Psvane ACME 300b
Kaiju, Linlai Elite  300b
Monamour 2a3 amps various tubes
Sota Sapphire, Pete Riggle Woody Tonearm, Kiseki Purpleheart Cartridge
Rega P6 Ania Pro cartridge
Roon Nucleus
MHDT Labs Orchid DAC
Jager speakers


Offline Frihed89

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Reply #7 on: April 06, 2013, 05:23:13 AM
Has anyone tried the Shuguang 300BC solid graphite plates?  I have a pair in an Audio Note Meishu integrated, replacements for some low mileage WE 300Bs I'm saving for a rainy day.  The Shuguans aren't WEs, but they are better all around then the EH's that came with the amp when I bought it used.



Offline Doc B.

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Reply #8 on: April 06, 2013, 06:30:31 AM
Not sure how many folks will want to cough up nearly as much for tubes as they pay for our kit. I'm thinking that the best approach might be to offer a separate mod kit that allows changing the circuit to work with the EMLs - which would necessarily make it incompatible with 300Bs.

Perhaps Jac could be persuaded to loan us a pair of tubes to develop the necessary mods with.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline ditdah

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Reply #9 on: April 06, 2013, 06:37:12 AM
hmm...well...  I bought 3 pair of EML 300b's.  pfft.

ok...I'm sure it was mentioned previously, but to avoid any further ordering mistakes, exactly which tube should I get for the BeePre?  The Psvane 300b-TII's?

Kenneth Koller


Offline johnsonad

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Reply #10 on: April 06, 2013, 06:59:05 AM
Not sure how many folks will want to cough up nearly as much for tubes as they pay for our kit. I'm thinking that the best approach might be to offer a separate mod kit that allows changing the circuit to work with the EMLs - which would necessarily make it incompatible with 300Bs.

Perhaps Jac could be persuaded to loan us a pair of tubes to develop the necessary mods with.

:) maybe so! Would you guys be willing to send the email to Jac? 

If such a kit was to be produced, it would be nice if it could have the resistors and specs to change the regulators along the full range of current draw, from stock 1.2 A to 1.5 A.

I would buy the kit in a heart beat and I bet most current BeePre owners would too. EML tubes are hard to beat if you are willing to pay for them.

Aaron Johnson


Offline johnsonad

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Reply #11 on: April 06, 2013, 07:00:25 AM
The other thread is mainly about the EML mesh plate 300b which has a filament current of 1.5A.  That we know will not work
Is there enough reserve for the 1.3A draw of the solid plate EML 300b in an unmodified BeePre?

Deb

Deb the way I understand it the current is regulated to 1.2 amps, not 1.25 amps. Hopefully PJ will weigh in on the 1.3 amp load.

Aaron Johnson


Offline Doc B.

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Reply #12 on: April 06, 2013, 07:39:06 AM
A 300B preamp is not a trivial pursuit as can be guessed by the number of them on the market. It turned out to require some pretty unique design elements to work to the sonic standard we require. It's quite a bit different than the traditional 300B amp with AC filaments that most 300Bs are made to work with.We supply the kit with EH 300Bs. We have not tried all of the boutique tubes, so I am hesistant to make any recommendation about other tubes unless they meet the standard WE spec for 300B filament voltage and current. The nature of our regulation scheme is such that it has to be modified for any tubes that don't run at the filament spec of the tube the preamp is designed for - a spec 300B. There is also the potential issue of how microphonic a given tube design might be. Again I can't comment on what I haven't heard. If boutique tube manufacturers would like the opportunity to have us recommend their product and they are willing to send us a pair of tubes to work with we can determine if adjustments to the regulator are necessary and if the level of microphony is acceptable for the application.

As regards EMLs, I will let PJ weigh in on that. He has had some discussion with Jac about the requirements of the EML tubes and I'm not sure if they are compatible with the regulation method we use to get the S/N ratio as good as it is.


Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline debk

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Reply #13 on: April 06, 2013, 01:26:46 PM
Anyone have any experience with the KR audio 300b?

Deb

Debra K

Eros 2Phono amp
BeePre2, Psvane ACME 300b
Kaiju, Linlai Elite  300b
Monamour 2a3 amps various tubes
Sota Sapphire, Pete Riggle Woody Tonearm, Kiseki Purpleheart Cartridge
Rega P6 Ania Pro cartridge
Roon Nucleus
MHDT Labs Orchid DAC
Jager speakers


Offline johnsonad

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Reply #14 on: April 06, 2013, 02:25:54 PM
Anyone have any experience with the KR audio 300b?

Deb

Please buy a pair and give us a comparison to your PSvane tubes. I've been on the fence with both pair..

I'm actually really happy with the EH gold grids. Mind you, I have nothing to compare them to......

Aaron Johnson