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September 26, 2022, 07:36:50 PM

Author Topic: Near field use on 87db speakers in a masive room.  (Read 1097 times)

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Offline Doc B.

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Re: Near field use on 87db speakers in a masive room.
« Reply #15 on: July 31, 2022, 08:03:02 AM »
PB has done a pretty good job of avoiding subjective comparisons with a competitive product, which has been our policy for the past 30 years. I'll just point out that the 11 watts output he's estimating for the Elekit vs. the 8 or 9 watts for a Kaiju means nearly jack when it comes to audible differences in power output. I'll also say that I feel very lucky having PJ around to design our iron. There are some very good winders out there and we went through most of the existing (and some no longer existing) winders over the years. We found that we could get closest to what we wanted - reasonable cost and very high performance - by PJ designing our own.
Dan "Doc B." Schmalle
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Offline currly30

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Re: Near field use on 87db speakers in a masive room.
« Reply #16 on: August 01, 2022, 05:20:59 PM »
Thank you. That actually did answers quite a bit about the differences in parts.

I figures the Kaiju had higher quality transformers. I haven't read much on the quality of Lundahl transformers. I just know they are better than the cheap stock ones on the Elekit. I would get the DC filament on the Kaiju which, if I understood right, bring the noise level down to being on par with the Elekits more complex power supply.

Tube rolling and customizing is quite important to me and based on what you are saying the Kaiju is more accessible for modification. Also being able to use any 300B on the Kaiju is a huge plus.

11W vs 8W is maybe 10% more in volume difference. So really the power is negligible.

 I didn't even think about how difficult repairs would be on the Elekit. Since it is all one board so if something goes wrong you would have to replace it all.

Offline Paul Birkeland

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Re: Near field use on 87db speakers in a masive room.
« Reply #17 on: August 01, 2022, 05:28:20 PM »
8W to 11W is 1.4dB, but both amps are going to clip pretty softly and have reasonable headroom. 
Paul "PB" Birkeland

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Offline dth31

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Re: Near field use on 87db speakers in a masive room.
« Reply #18 on: August 02, 2022, 05:46:46 AM »
I can’t speak for other people, but speaking for myself, I hate soldering and desoldering PC boards.  The Elekit is one big PC board and my personal experience is that it’s really easy to mistakenly create solder bridges on PC boards.  It’s also easier to create cold solder joints unless you’re experienced soldering PC boards.  Desoldering PC boards is also a major PITA (although finally discovering solder suckers made it much easier).   One of the many reasons I love Bottlehead kits is that they are largely NOT built on PC boards and are therefore much easier to solder, desolder, troubleshoot and modify.

Just my 2 cents and YMMV.

Offline currly30

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Re: Near field use on 87db speakers in a masive room.
« Reply #19 on: August 04, 2022, 01:53:40 PM »
Since I am going to be using the Amp in a near field situation. Would the Stereomour II be a better amp to look at getting? I have read the 2a3 is a more musical sounding tube than the 300B. How does the sound differ between the Kaiju and the Stereomour II? Or would I need the extra power of the Kaiju for my speakers? If I understand correctly the Kaiju should net me an extra ~4db of sound.

Offline 2wo

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Re: Near field use on 87db speakers in a masive room.
« Reply #20 on: August 04, 2022, 05:36:14 PM »
In my opinion the 300B has a fuller sound with more weight to it then the slightly leaner more laid back sound of the 2A3. 

I have a Kaiju which I use with a veriaty of speakers including some in the 85db range and I am happy with the sound...John
John Scanlon

Offline Paul Birkeland

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Re: Near field use on 87db speakers in a masive room.
« Reply #21 on: August 04, 2022, 06:33:50 PM »
The iron in the Kaiju is also a bit better than the Stereomour, and the 5670 is the better sounding driver tube.

The Stereomour is possibly a bit easier to build because it is a bit simpler, but you also have to do all that input wiring to the selector switch which takes some extra time...
Paul "PB" Birkeland

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Offline currly30

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Re: Near field use on 87db speakers in a masive room.
« Reply #22 on: August 04, 2022, 07:59:47 PM »
For tube rolling is there much variety in the 5670 tubes between brands? Or is the 300B more important for tube rolling?

Offline Larpy

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Re: Near field use on 87db speakers in a masive room.
« Reply #23 on: August 05, 2022, 06:18:06 AM »
They both make a difference, but I hear bigger differences between 300B tubes.  Tube rolling with 300Bs gets expensive, however.  But I found the expense of new production Western Electrics to be worth the upgrade in sonics and what I anticipate will be a longer life than the stock EH tubes.

It's pretty cheap to try different 5670s.  My Kaiju kit came with GEs, and they sound pretty good.  I've tried RCA, Sylvania, and vintage WEs, and none proved decisively better than the GEs.  In fact, the WEs were a distinct disappointment.
Larry

Offline Doc B.

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Re: Near field use on 87db speakers in a masive room.
« Reply #24 on: August 05, 2022, 07:26:10 AM »
The WE 300Bs may well be a sonic upgrade. But I wouldn't necessarily assume the EHs to be shorter on lifespan. I typically get six to ten years out of one.
Dan "Doc B." Schmalle
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Offline currly30

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Re: Near field use on 87db speakers in a masive room.
« Reply #25 on: August 05, 2022, 10:58:17 AM »
Interesting. Thank you all for answering all my questions.  I have just a couple more.

Is it possible to use 6SN7 tubes with adapters instead of the 5670 tubes? I only ask because I own 15 pairs of matched 6sn7 tubes.

Does the DC upgraded change the sound characteristics of the Kaiju?

Later on of I decide to upgrade the caps on the Kaiju. Which ones would be worth upgrading?


Offline Paul Joppa

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Re: Near field use on 87db speakers in a masive room.
« Reply #26 on: August 05, 2022, 11:21:18 AM »
It would be possible to use 6SN7s in Kaiju, but you'd need more modifications than just an adapter. You'd also lose 6dB of gain.

The interstage coupling cap (0.1uF/630v) and parafeed output cap (10uF/630v)are the principal caps that are in the signal path. The shunt regulator stability Zobel cap (also 0.1uF/630v) also has has a minor effect on the sound,  but it's on the regulator PC board and difficult to access.

These caps are subject to break-in changes, so allow at least 100 hours of music before critical listening.
Paul Joppa

Offline currly30

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Re: Near field use on 87db speakers in a masive room.
« Reply #27 on: August 05, 2022, 05:53:15 PM »
A 6db loss seems like a lot. So probably not worth it to change to a 6SN7 tube input. How does upgrading the caps affect the sound? Should I wait to do the DC upgrade till I've put time on the amp?

Offline Paul Joppa

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Re: Near field use on 87db speakers in a masive room.
« Reply #28 on: August 05, 2022, 07:37:48 PM »
Changing the caps will - subtly - change the sound. Whether it's an upgrade or a mistake is difficult to generalize; it depends too much on personal reaction. There is some consensus on the interwebs, but it changes often. I personally think the best benefit of cap rolling is that it educates your hearing, and you learn what you like. That's just my two cents though.

It's usually a good idea to build an amp stock first and run it for a few weeks. This gets it through break-in, educates your ear as to the baseline sound, and it helps catch a lot of small errors such as dirty tube pins, marginal solder joints, loose screws, etc. And it's much easier to debug any problems after a change when you know for sure it was working correctly before the change.
Paul Joppa

Offline currly30

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Re: Near field use on 87db speakers in a masive room.
« Reply #29 on: August 10, 2022, 07:17:17 PM »
What varieties of the 5670 will work for the input socket on the Kaiju? I read in another post that some of the varieties aren't rated for high enough volts. 

Will pretty much any of these tubes types work? I think this is full list of comparable tubes.  396A, GL5670, CK567, 2C51, 6CC42, 6Н3П, 6N3P(EV, DR), 5670W, 5670WA, CK5670-WA, CV4013, GB-5670.