My Kaiju Has Arrived!

[drewh1]

You will appreciate the DC supply, i highly recommend it.  As soon as I am back up and running, i'll give you more feedback on the EML's. I want to hear them with the Mundorf Silver/Oil. I did have to put some resistors in parallel to get the filament voltage up to spec with the EML's, but that was quite easy and you can find the values on my thread. - and you can bet I am glad it was only a driver tube.  I did order some NOS 5670's to try so more stuff to break-in. (BTW, I did not drop that f-n tube)

I also agree with your Stereomour comments. I am using mine again (waiting on tube) and although it has some nice qualities, It is no match for the Kaiju, The Kaiju has much more presence, is more 3d, and definitely has more impactful bass. Instrument separation and clarity is remarkable. One major audible difference between the Sovtek's and EML's is in high frequency clarity and response, definitely more clarity and definition in cymbals and bells sounds with the EML's, even surpassing the 2a3's.  I am just so happy they introduced it as I really wanted a simple system, without all the extra cables and chords, so it is a nice compromise to monoblocks. (Edit having said that I would love to hear my stereomour through some 100 dB speakers and plan on just that in my second system)

I don't know what your budget is but you should also take a look at the Tatatsuki's - expensive but supposedly amazing both in sound and build quality.  I am happily saving up for a pair.

drew.

 

[Doc B]

I'm sorry that you think I am accusing you of something. I'm certainly not disputing what happened and I believe what you say. I'm just trying to educate about the mechanism behind such a violent demise. A tube blows like that because it gets gas inside. The gas comes in either through a crack or a bad seal. In the case of a crack, as soon as the air gets inside the getter flashing turns white, like within 30 seconds. Once it is in that state it will blow when powered up. If the tube has a hard vacuum it might arc inside if it has a fault like a grid short, but it won't explode. If it has a small amount of gas from a slow leak from a bad seal the getter flashing usually does it's job and "gets" the gas, rehardening the vacuum. That is why some tubes show thinning of their getter flashing or no getter flash left at all.

It's possible that the tube cracked from heat cycling. I've just not seen this happen in my limited experience.

 

[drewh1]

Hey doc. Thanks clarifying and
No worries. I am just a bit defensive after that whole affair with you know who. I was really careful with the build as I have invested a lot into it so that might also be a part of me taking it personally. It is of course to easy to read into comments made on forums.

Bottom line kaiju is a great amp and I am glad you offer it.  Sorry to hijack the thread, let's get back to enjoying our music.

 

[drewh1]

BTW. Looks like tubeaudiostore.com is another source for Eml's.

 

[ebag4]

How do I order the DC filament board without reordering the Kaiju?  Can it be done online or do I need to call while BH is open?

Thanks,
Ed

 

[Doc B]

We will work on getting an order page up tomorrow.

 

[ebag4]

Thanks Doc.

Best,
Ed

 

[pduk]

I'm interested in ordering the DC filament kit as well. I can't hear any hum from my listening position but I can if I move around the room (and change CDs!) which is sufficiently distracting to merit getting it. Will keep an eye on the products pages.

P.

 

[Doc B]

The DC filament supply order page is up:

http://bottlehead.com/product/dc-filament-supply-for-kaiju-300b-amplifier/

 

[pduk]

Excellent, thanks Doc - ordered!

 

[ebag4]

These are the speakers I am driving with my Kaiju.  I have been running the top section for a while now, I was using the bass section from my previous speakers but have recently finished the bass section for the GR Research Wedgies (94 dB).  Pics for your amusement:







Best,
Ed

 

[drewh1]

gorgeous set up man! I am jealous.  I think you need to balance the whole system out with another Kaiju though 

what ribbon tweeter are you using?  I am having my speakers upgraded with a Raal 70-20. (if the guy ever gets it done)

Can't wait to hear what you think of the Sophia's.

 

[ebag4]

Thanks Drew.  The tweeter is a B&G Neo3 PDR run in open baffle.  It is actually a planar driver, not a ribbon.  The speakers are the GR Research "Wedgies", they play from 200 Hz and up, the bass units are a pair of 12" servo subs in a "U" alignment per channel, each channel has it's own 350 watts servo amp.  These speakers are odd in that you can walk behind them and they sound the same, I really love them. Can't wait to hear them with the Royal Princess, they are scheduled to arrive Monday.

Best,
Ed

 

[ebag4]

I should receive my Sophia Royal Princess 300Bs tomorrow (specs below).  Are there a series of measurements I should run after the tubes have run in for a few hours?  What specifically should be checked?

Thanks,
Ed

Royal Princessâ„¢ 300B

Nominal operating conditions and parameters:
Filament voltage
5,0 V *
Nominal filament current
1,2 A
Plate voltage
300 V
Grid voltage (AC filament)
61 V **
Grid voltage (DC filament)
58 V ***
Plate current (AC filament)
60 mA
Plate current (DC filament)
62,5 mA
Grid to plate transconductance
5700 Ω
Amplification factor
3.85
Grid current
0.05 µA
Plate resistance
700 Ω
Limiting Operation conditions for safe operation-nor simultaneous ratings:
Maximum plate voltage
450 V
Maximum plate dissipation
40 W
Maximum plate current of average tube for fixed grid bias
70 mA
Maximum plate current for manually adjusted grid or self-biasing circuit
100 mA
* - AC filament supply or DC filament supply.
** - AC filament supply is used. The grid and plate returns should be connected to a center tap on the secondary of the filament transformer.
*** - DC filament supply is used. The grid and platter returns are connected to the negative end of the filament.


Thanks,
Ed

 

[Paul Joppa]

Those specs are the standard 300B specs, so you should not need to make any special measurements.

If your power line voltage deviates from 120v by more than 5v, you can measure the voltage across the 300B filaments (pin 1 to pin 4) to confirm the correct filament voltage.

As far as I have found, Western Electric never made any spec for maximum deviation of the filament voltage. A range of +/-10% was however common in those days (late thirties to early fifties). A few special-purpose tubes might have had a +/-5% rating. EML specifies +/-4%. In Kaiju the tube is operated at a fairly conservative plate voltage and current, so there's no reason I know of for a tighter spec that 4-5%

 

[ebag4]

Thanks PJ, much appreciated.

Best,
Ed

 

[ebag4]

I built another base this time using the frame that was supplied with the Kaiju.  I painted this base instead of wrapping.  Here are a couple of pics for your entertainment:








Best,
Ed

 

[ebag4]

I received the Royal Princess tubes.  Right out of the box there was a noticeable reduction in hum from my speakers, enough that it is nearly negligible, I would say less that my Stereomour with the JJ 2a3.

These tubes were used previously, reportedly with less than 400 hours on them, I don't know when they were last used.  They did not blow me away (other than the low noise floor) initially so I let them play about 5 hours and listened again, much better, noticeably better than the EH but not a night and day difference.  I put on The High Kings "The Parting Glass", fantastic sound enveloping my room. Great tone.  I'll put a few more hours on them before passing judgement. 

Best,
Ed

 

[ebag4]

I noticed I was getting a sound that I can only describe as ringing, I'm not certain that is accurate, it was a slight bell sound following certain notes, this was not constant but noticeable.  I started looking at the system and noted that the amp was in close proximity to a 12" woofer on one of the speakers.  Moving the amp about 12" appears to have taken care of that issue, after several tracks I have not heard it again.  It is still close but apparently not too close any longer:




Best,
Ed

 

[ebag4]

Well, I have been running the amp for a while so I decided to add the DC filament supply to allow me to try other tubes I have been considering.  I recieved the DC filament kit, it went together fantastically like all the Bottlehead kits do.  I powered it up for a few songs to make certain it was working correctly, total silence from my speakers, very nice.  With the Clarity 10uF MR caps it's getting pretty cozy in there:




I also recieved my tubes today, so I pulled the EH 300Bs, and put the new tubes in:



The infamous Elrog 300B, they are the best sounding tubes I have heard, and I have been listening to them for less than a hour.  PJ says the basic Kaiju design parameters appear to be nearly ideal for this tube, so I'm hopeful I get reasonable mileage out of these. 

Vocals are incredible, great presence helping make this the best amp I have heard.

Best,
Ed