Bottlehead Forum

Bottlehead Kits => BeePre => Topic started by: Razakoz on August 31, 2022, 10:00:53 AM

Title: Finished my Beepree and have it working, a few questions regarding balance pot
Post by: Razakoz on August 31, 2022, 10:00:53 AM
Hello all, I just finished my standard BeePre build and got it working with no issues.  The manual was very well done and clearly explained every step, I'd say it took me around 20 hours total to finish the kit.  As an added upgrade I used VCAP ODAM instead of the Dayton Audio output caps.  So far it sounds very good with no notable buzz or hum, and I'm using my used pair of Takatsuki 300Bs in it.  My questions relate to the balance pot.  Is it possible to bypass it, and are there any negatives to doing so? I notice that there are the two resistors on it which seem to be in parallel with the pot, what is the function of those?  I assume if one simply jumped over them with wire they would bypass the balance pot, but I don't want to do so without knowing if that will hurt anything.  I've never used balance controls on any of my gear and would ideally remove it from the signal path if possible.

Thanks
Title: Re: Finished my Beepree and have it working, a few questions regarding balance pot
Post by: Toobuzz on August 31, 2022, 10:23:43 AM
My advice would be to go with the 1st upgrade. It’s a serious improvement to the signal path and removes the balance control.
Title: Re: Finished my Beepree and have it working, a few questions regarding balance pot
Post by: Paul Birkeland on August 31, 2022, 11:38:35 AM
+1
Title: Re: Finished my Beepree and have it working, a few questions regarding balance pot
Post by: Paul Joppa on August 31, 2022, 12:22:02 PM
Without those resistors, the output voltage when centered is -6dB on both channels. With the resistors added, it's -3dB (half power) when centered. Thus the total power (both channels) is constant when adjusting the balance.

They can be bypassed by removing the resistors and taking the output from the hot terminal, leaving no connection to the wiper. That leaves the control's end-to-end resistance as a grid-to-ground resistor but eliminates the wiper contact.
Title: Re: Finished my Beepree and have it working, a few questions regarding balance pot
Post by: Thermioniclife on August 31, 2022, 12:35:39 PM
Hi PJ, I fail to see how by adding resistance in that position can yield more gain than without the resistance. Could you expound a little.
Thank You.
Title: Re: Finished my Beepree and have it working, a few questions regarding balance pot
Post by: Thermioniclife on August 31, 2022, 12:50:08 PM
Hey PJ, I thought about it further and see what the deal is now. :D
Title: Re: Finished my Beepree and have it working, a few questions regarding balance pot
Post by: Paul Birkeland on August 31, 2022, 01:08:17 PM
Hey PJ, I thought about it further and see what the deal is now. :D
I have the same experience routinely.
Title: Re: Finished my Beepree and have it working, a few questions regarding balance pot
Post by: Razakoz on August 31, 2022, 02:22:36 PM
Hmm, sounds like I should probably go for the first upgrade with the stepped attenuator :D
Title: Re: Finished my Beepree and have it working, a few questions regarding balance pot
Post by: Razakoz on August 31, 2022, 03:17:09 PM
Alright I ended up ordering the Bee2quite stepped attenuator upgrade not wanting to leave performance on the table.  How do I get the manual for it though?  I dont have the usual PDF link in my order history.
Title: Re: Finished my Beepree and have it working, a few questions regarding balance pot
Post by: Doc B. on August 31, 2022, 05:18:08 PM
Not sure why it didn't work for you. Contact us tomorrow at [email protected] and we can get a download link for you.
Title: Re: Finished my Beepree and have it working, a few questions regarding balance pot
Post by: Razakoz on September 09, 2022, 09:22:30 PM
Bee2Quiet Upgrade installed and working.  Great upgrade, I'd say it took me about 6-7 hours to install and it significantly improved the preamp.  Better resolution, perfect channel balance, the sound seems more refined, and it looks nice with the new face plate under the knobs.  Thanks for the recommendations.  Next up I might build the Kaiju to go with this at some point.