Bottlehead Forum
Bottlehead Kits => BeePre => Topic started by: Gerry E. on November 14, 2013, 07:46:57 AM
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Hi:
I finally pulled the trigger and ordered a BeePre to go along with my Paramount 300B amps. My friend Boulos, who has built a S.E.X. amp and then added the C4S upgrade, will be doing the build for me. He has additional electronic/soldering experience including replacing my stock Paramount transformers with the Magnequest full-nickel upgrade transformer set.
I have been in the passive attenuator camp for a while (most recently with a LDR-based unit) but recently heard what an active preamp can do for my system. Before Boulos gets started, I would like to ask some questions:
1. We will go with the stock volume controls instead of the BeeQuiet which we can always add later. I just want to confirm that if you add the BeeQuiet, you lose the balance control functionality, correct?
2. I purchased the BeePre without tubes and was thinking of purchasing a pair of JJ 300Bs for it. They JJ 300Bs appear to be both a good choice and good value for the BeePre - any thoughts on this?
3. I know the BeePre comes with excellent parts but are there any must-have part upgrades you can suggest? I assume capacitors would be the most likely but which ones?
4. I'm a single input guy. Um, I mean I only want/need a single input and two sets of outputs. How difficult would it be to build with just a single input vs. the stock multiple inputs? Would it actually be easier to build and possibly sound better? I'm more curious about those last two questions than either mattering that much.
5. Excluding the 300Bs, what is the full tube compliment and quantity of each tube?
6. Any other advice or tips about the build that you can think of?
Any information or thoughts would be very much appreciated - thanks!
Gerry
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1. We will go with the stock volume controls instead of the BeeQuiet which we can always add later. I just want to confirm that if you add the BeeQuiet, you lose the balance control functionality, correct?
Yes
2. I purchased the BeePre without tubes and was thinking of purchasing a pair of JJ 300Bs for it. They JJ 300Bs appear to be both a good choice and good value for the BeePre
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Im using jj 300Bs in both my paramounts and beepree, and am very happy with yhem in both applications.
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Thank you PB and STURMJ! Both the BeePre and JJ 300Bs are in transit. I was pleasantly surprised how quickly the BeePre was shipped. I expected it to be another month or so.
The JJ 300B appears to be an ideal low cost option for the BeePre due to their very low noise
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One question I didn't ask was if the BeePre comes stock with two set of outputs. I re-read the product description the other day and it mentions two sets of outputs. Pierre Sprey's advice notwithstanding, I like running my subwoofer at line level vs. speaker level. In case you don't know, Pierre is the very opinionated man behind Mapleshade and he says that you must only use speaker level inputs to subwoofers.
It does come with both an unbalanced and balanced output. You could easily use two unbalanced output or two balanced outputs without much extra trouble, or you could just make a woofer cable that adapts the balanced output.
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If connecting two unbalanced outputs, do I simply jumper the signal and ground of the two outputs? That is, I wouldn't need the 604ohm, 475Kohm, and 10uF components that would otherwise connect to terminal 3 of the XLR output, correct?
Thanks
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Yes, that is correct.
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Hi PB:
Boulos, who is building the BeePre for me, and I are double-teaming you a bit here. In an earlier post, you wrote:
"There are 10uF coupling caps. Since you have Paramounts, these can be smaller if you like. The voltage rating should be 100V or more. We strongly suggest building the kit in stock for first, then upgrading later, and we have left a good amount of space to make this easy."
Can you explain why one can use smaller coupling caps when they will be using the BeePre with Paramounts? Also, how low could I go without compromising performance? The reason for the latter question is the lower I can go, the better cap I can buy. Thanks for all your help!
Gerry
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You can read through this page for a bit of an explanation on how this works:
http://www.v-cap.com/coupling-capacitor-calculator.php (http://www.v-cap.com/coupling-capacitor-calculator.php)
FWIW, even though the calculator will give you a very small value to use in conjunction with the 249K input impedance of the Paramount, I would use a minimum value of 1uF.
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HI Gerry, I played around with smaller caps and will say from experience that 10uF is a sweet spot. Dan has posted a few times that 10uF is minimum for bass respose.
I'm using Russian KBG 10uF in mine and really like them. I've got a pair of Jupiter's (10uF) collecting dust if you are interested. If I were to try any others they would be the Rike Audio PIO's. I'm really liking them in my SEX amp.
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HI Gerry, I played around with smaller caps and will say from experience that 10uF is a sweet spot. Dan has posted a few times that 10uF is minimum for bass respose.
Hi Aaron:
I thought Doc's 10uF recommendation was for the Paramount? I just want to make sure we are talking BeePre here. Maybe it applies to both?
OT - Did you get my e-mail about Open Baffles?
Gerry
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Definitely the BeePre and not the Paramount.
No open baffled yet. I'm patiently waiting on boxes to be finished.
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Not sure if I should start a new thread, but I will start here.
For the low voltage DC supply, page 42 specifies that one should user 10,000uF 10V capacitors. However, the kit came with 10,000uF 6.3V capacitors (and only 2 instead of 4). Has something changed in the build without an update to the manual? Or does this specific kit not include the correct parts? I believe Gerry emailed replacementparts but afaik haven't heard back, so I thought I'd inquire here in case this was not a mistake.
Thanks
Boulos
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There should be four 10,000uF/10V caps and two 10,000uF/16V caps. The 10,000uF/6.3V caps are a packing error, and likely came in place of the 10,000uF/16V caps.
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Thanks! That's what I thought there should be. What was packed instead were two 10,000uF/6.3V and two 10,000uF/16V.
So then I won't do anything with the 6.3V caps and wait for a response from replacementparts.
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Here's a shout out to Boulos who just finished my BeePre. When I first ordered it, I wasn't even sure if we would have the kit yet, let alone it being finished before Christmas!
Boulos did a fantastic job, here are a couple of photos (Boulos is the good looking guy in the photo within the photo):
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi27.photobucket.com%2Falbums%2Fc157%2Fgerrye123%2Fbeepre1_zpsa28526b2.jpg&hash=c071794985ef3d11de47ba282b139c82ab369798)
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi27.photobucket.com%2Falbums%2Fc157%2Fgerrye123%2Fbeepre2_zpse671c023.jpg&hash=355badd7f15b44346d89e11dc9248d6fdeffb1fc)
I'm picking the BeePre up in a couple of hours and can't wait to try it in my system. Boulos has already reported how great it sounds (thanks Bottlehead!). As time and funds permit, I will be doing a couple of upgrades (Blumenstein base, upgraded power cord, upgraded fuse, etc.). We already have a couple of Russian 10uF PIO caps coming from Bulgaria.
I'll report on my impressions of the BeePre in a follow-up post. Thanks Boulos!
Gerry
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Lovely build. Which 300B's are they? Look like some JJ boxes in the background.
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Lovely build. Which 300B's are they? Look like some JJ boxes in the background.
Hi Chris:
The tubes are indeed JJ 300Bs. They sound more than fine in the BeePre. I picked up the BeePre last night and put it into my system this morning. It works perfectly and sounds terrific! A couple of sonic attributes that I noticed rather quickly (other than the obvious ones like mid-range purity and tone density) include the excellent depth reproduction and resolving capability.
I'll expand on those two attributes a little more. By excellent depth reproduction, I don't mean that the entire soundstage was moved back. It just expanded in the background. As for resolving capability, I noticed that every last note is clearly heard during each CD cut fade-out.
At some point I will swap the Sophia Royal Princess 300Bs I'm using in my Paramounts (I bought them used and paid a lot less than the suggested price) with the JJs and see which configuration I like better. I hope the RP 300Bs are OK to use in the BeePre, comments anyone?
I'm carefully reading the construction manual to have a better understanding of the BeePre and even more appreciation of all the hard work Boulos put into it. I love the last sentence on page 6: "Thanks also to Queen Eileen Schmalle for putting up with yet another of Dr. Bottlehead's cockamamie scheme(s)." Indeed!
Gerry
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The BeePre was fun to build, yet very intricate. We did a couple minor mods to the build:
-- The first is to have 2 RCA outputs and 2 RCA inputs. I moved the XLR jacks in the place of the 3rd RCA inputs (essentially to cover the holes). The third input is connected at the switch so adding a third RCA input is very easy. I attached a picture.
-- The second is simply to use a different wire for the 120V wiring. The main difference is that it's 18AWG wire. These are the two red wires you see in the picture Gerry posted.
To test the BeePre, I connected it to my S.E.X/Orca desktop setup. It truly transformed that system making sound beautiful even with the Orcas lodged between books on a shelf. A funny story is the first time I connected the BeePre no sound came out and I was baffled because all the resistance and voltage checks had just passed. It was very stressful, and after a few minutes, I decided to turn it off, reconnect everything and try again. That's when I realized that it was off the whole time! :-)
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Can't get much quiter than off, but, if anyone can do it, I'm betting on PJ!
Just did my AC wiring. Thought I screwed up when I saw that red wire in you pic...then I read the post.
I'm wiring mine one in and three out. Will wait and see on the last one. Maybe I can swap the Queen for another pair of RCAs.