Bottlehead Forum

Bottlehead Kits => Kaiju Stereo 300B amp => Topic started by: currly30 on January 14, 2023, 05:33:59 PM

Title: Mesh/Punctured plate 300B
Post by: currly30 on January 14, 2023, 05:33:59 PM
Has anyone tried any of the 300B mesh tubes on the Kaiju? Like the Cossor 300B, LINLAI 300B-H, Tj Fullmusic 300B-N, EML 300B-mesh?
Title: Re: Mesh/Punctured plate 300B
Post by: currly30 on January 14, 2023, 05:40:01 PM
Is there any difference between the Chinese mesh tubes?
Title: Re: Mesh/Punctured plate 300B
Post by: currly30 on January 14, 2023, 06:07:04 PM
Also, some of the mesh tubes are 1.5A. Is that okay for the Kaiju to run?
Title: Re: Mesh/Punctured plate 300B
Post by: Paul Birkeland on January 15, 2023, 06:12:04 AM
I would not recommend 1.5A tubes in the Kaiju/BeePre, as these kits are designed for 300Bs built to the proper spec.  EMLs are pretty popular, TJs used to be, and the other two offerings are relatively new in comparison.
Title: Re: Mesh/Punctured plate 300B
Post by: currly30 on January 15, 2023, 11:34:10 AM
The EML mesh is 1.4A. Is that okay for the Kaiju?
Title: Re: Mesh/Punctured plate 300B
Post by: Paul Joppa on January 15, 2023, 01:39:45 PM
In 2016 I posted this:

"Adjustments can be made for small changes in the filament current. The risk is that the regulator chip may overheat if too much current is drawn, especially if the power line voltage is also high. We have not determined how far you can deviate from the standard 1.2 amps without risking failure of the chip, so the risk is yours."

The design incorporates some margins for power line voltage and ambient temperature variations to ensure reliability, but there is no design margin for more than 1.2 amps.

Title: Re: Mesh/Punctured plate 300B
Post by: currly30 on January 15, 2023, 02:04:25 PM
Thank you, that is good to know.
Title: Re: Mesh/Punctured plate 300B
Post by: vince on March 09, 2023, 12:42:15 PM
I am using Emission Labs 300B Mesh tubes.  Sounds wonderful!  I believe I had to adjust the filament supply to get these tubes to work within Emission Labs' specified operating conditions.  http://www.emissionlabs.com/datasheets/EML300B-mesh-final.html

All that said, I didn't run solid plates before going to the mesh plates.  Just got the thing working with mesh straight away.


Title: Re: Mesh/Punctured plate 300B
Post by: vince on March 09, 2023, 12:52:27 PM
This is a really good point.  To mitigate I bought an extra filament supply and put it in a drawer.  It is still there, several years later.

In 2016 I posted this:

"Adjustments can be made for small changes in the filament current. The risk is that the regulator chip may overheat if too much current is drawn, especially if the power line voltage is also high. We have not determined how far you can deviate from the standard 1.2 amps without risking failure of the chip, so the risk is yours."

The design incorporates some margins for power line voltage and ambient temperature variations to ensure reliability, but there is no design margin for more than 1.2 amps.
Title: Re: Mesh/Punctured plate 300B
Post by: 2wo on March 09, 2023, 05:15:03 PM
I have an older set of TJ perf, they work fine in the Kaiju...John
Title: Re: Mesh/Punctured plate 300B
Post by: currly30 on March 09, 2023, 07:31:10 PM
This is a really good point.  To mitigate I bought an extra filament supply and put it in a drawer.  It is still there, several years later.

Did you mod the Kaiju to work at the higher amps?