Same experience here. Huge difference swapping the rectifier. I have 4 different brands that all ‘do their thing’. The best one will eliminate most noise issues with a number of 6SL7 tubes and make the amp much more dynamic and holographic.
Any experience with the Bendix tubes 6384?
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I have a friend who has a stash of bendex and the drawings too. Anything Bendex is incredible in my experience. I use a couple of the 6900’s he gave me and they are on another level.
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6384 and the 6889 are fantastic choices. really just a 6l6gb that was designed never to die… so it can be used as a GC.
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I have managed to get hold of ‘enough’ 6384’s but the 6889’s are impossible to find. Are they similar sounding?
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A question for you @ampsandsound :
The auto bias of the Mogwai SE - does this system level out a pair of power tubes that are not measuring 100% identical?
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Old GE to my ears give you a sound with more control, better edges definition if we look at the thing as if it was a picture. It’s something I really appreciate.
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Totally agree. My favorite tubes of that era are Bendax, Kenrad, GE and occasionally Mullard, though those could be hit or miss. Some of the Raytheons were really good too.
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Its a cathode bias scheme… in short, there is not balance/referencing the other power tube. Id suggest power tube matching isn’t as large as a concern as balanced triodes. Ive used mismatched tubes for years and really couldnt hear it unless it was really really wrong.
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Hi, how long does it take to receive the amplifier after the order is placed? I want to mark my calendar, so excited hehe
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You should ask Justin…he can give you an estimate based on the type of amp you bought. Congratulations. I own two of his amps. What model did you purchase?
apox 6 weeks to completion and shipping on the 7th.
Sometimes things are fluid as metal shop just took a week longer than expected and in general supply chain is not what it was 3 years ago.
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Nice, I ordered a Kenzie OG V2.
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Excellent choice. I have original Kenzie and Kenzie Encore.
Deleted reccomendation. Amp design change uses nine pin input tube on version 2, not an octal.
The REV2 amps use 12a_7 tubes now, don’t they? Just wanted to make sure @Cuentos_de_la_Cripta doesn’t buy a 2C52 and asks why it doesn’t fit.
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Good catch. I didn’t know they had changed the input tube to 12A_7 novel tube. The 12A_7s are higher performance tubes.
So I just received my amp (surprisingly fast which made me happy) but I am concerned because it’s VERY noisy. Does not matter if I’m using the Low or High Z, I get the same amount of noise and it is somewhat loud. I can have the volume at the lowest and still the same noise and its not a hum. I don’t know if I got bad tubes or the amp is faulty but I wasn’t expecting this much noise especially after watching Tyler’s review (ampsandsound Kenzie 2.0 headphone amplifier... my thoughts - YouTube) doing a volume test and saying the amp is basically silent. Plus a very noticeable channel imbalance that doesn’t get corrected unless I turn the volume up to where I’m not comfortable listening for long so I can’t listen to it quietly because only the left channel would make sound. I am kind of new to tube amps, I have a Feliks Audio Espressivo MK2 and that amp is silent, no noise whatsoever and no channel imbalance. I’ll try moving the amp to another spot to see if it might be picking up weird signals. Any advice is appreciated.
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Try swapping the tubes to see if the channel imbalance switches sides. Some tubes are weird when new, some tubes are bad or damaged in shipping, and they are indeed vulnerable to electrical interference. Make sure the DAC cabling is also isolated, shielded, and well attached. Tubes sometimes settle down with use. Keep your phone and other electronics away for testing.
I hope something works.
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Move the amp to another location, and circuit, and see if it quiets down. Is the noise heard in the headphones, or is it mechanical noise?
As @generic said above, tube swap to see if you have one strong tube, and one weak one.
I’ve experienced noise issue on my base Kenzie. Much of it cleared up by repositioning it away from another component.
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Give me a call/send me an email. You might have had some tubes damaged in shipping. Happy to help.
We QC the amps really thoroughly before they leave but shipping can be hard on tubes.
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It looks like you have some damaged tubes.
Knowing the quality of Justin’s stuff, this isn’t standard at all, and it was probably banged up by shipping.
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