Anyone try the NEW 300B Tubes from Western Electric? Worth the Money? Better or Different than older Ones?
- Thread starter caesar
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It's ok,then you can't complain if it hums. turn off your device and treat the hum pot with contact spray, move it back and forth for 1 minute. Maybe things will get better after that
Can you please enlighten me what are the hum pots and where are they located?
Sorry, I thought the amplifier was AC heated because someone mentioned it. I looked for the circuit diagram and found it. It is already symmetrical, the tube is heated with DC no hum pot.
Just following along with this. I really don't have any technical advice to offer although I would be like you hesitant to be adjusting hum pots and modifying my amp.
Your amp did not have any hum before so either the WE are for some reason not compatible with your amp or they are defective. In either case I would replace these tubes. I hope you don't have any problem doing so.
This Yamamoto has simple DC heater, so there is nothing to adjust (as others have stated). In amps with AC heaters, there is a hum balancer to make sure the phases of AC voltage are the same so hum doesn't result from the imbalance. Some claim AC heaters sound better than DC when properly implemented, but thats another discussion..
Do you have hum out of both channels? It's highly unlikely that both tubes are bad and/or both sockets are having issues. It could be related to the filament design of the WE vs the EML, which, if you have highly sensitive speakers, might be discernible. The DC circuit in the Yamamoto is likely not perfectly clean.
Yes
Agree.
If that's the case it is disappointing. I have contacted Yamamoto, still awaiting their reply. I have an option to try out some NOS WEs, let's see if the phenomenon persists.
Well, so far I very much like the sound of the Yamamoto. But having a 300B amplifier without the option to tube role is disappointing.
The Yamamoto is a very good amp, and nothing wrong about their DC implementation. I had the A-08 45 amp for a very long time, and probably shouldn't have sold it. If you have highly sensitive speakers, perhaps they are showing some of the limits of the design and the difference in the WE design is making it more pronounced.
Alternately, I'm guessing here, but perhaps the amplifier has a failing filter cap that isn't quite performing up to task, or there is an issue with the rectifier tube, and the WE300B is making the issue more noticeable. Usually these power supply related issue hums are closer to 120hz. Hopefully Yamamoto can provide some insight for you.
Actually I'm using it with headphones (not with speakers). I have a spare rectifier tube that I can try, but with the Emission Labs 300B XLS there's no hum...
Although I tend to prefer the WE sound over EML.. The EML tubes are built like absolute tanks. They might simply be more resistant to hum in their plate/ heater filament design compared to the WE or other tubes like it.
I had a chance to loan a used old stock WE 300B from the 60s.
I experienced the same hum.
I believe it is clear that this is not a tube issue, but probably compatibility issues with the Yamamoto.
That's a bit disappointing. Sounds like a combination of the heater filament design + Yamamoto heater circuit + a very high efficiency output (your headphones) not yielding the proper result. Check out the Stradi thread, you might find a great tube to try there. They seem a bit more focused on heater noise because a lot of their tubes are used in preamplifier/phono circuits.
Yes I would imagine it is very disappointing to @iaxel. Hopefully he is not stuck with an expensive set of tubes that don't work with his amp.
I searched out the Stradi thread that you suggested. Very interesting, I wasn't aware of this tube manufacturer. I will be following up for sure.
On the Stradi thread one of the posters identified there were some modern WE 300b issues with Allnic components. He didn't specify exactly what the problem was but I wonder if it could be similar to iaxels?
Yamamoto responded saying that in the past they’ve used WE300B to test their amps, but in recent years they use the EMLs.
He said that with electrical knowledge it is possible to reduce the hum with the hum balancer. I know this was mentioned before, I have asked Yamamoto for instructions how to change it.
I also have a pair if 300B ordered from Kondo, specially made by Takatsuki for them.
He said that with electrical knowledge it is possible to reduce the hum with the hum balancer. I know this was mentioned before, I have asked Yamamoto for instructions how to change it.
I also have a pair if 300B ordered from Kondo, specially made by Takatsuki for them.
Personally I would move away from using hum pots. If the WE don't work with your amp then move on, there are tubes that are as least as good or better than the modern WE 300b.
Or old stock WE300B, as I have experienced the same issue with them.
I have a Kondo-branded Takatsuki to try out. Hopefully they will not introduce the same issue.
I have used Takatsuki, the current WE, various PSvane models and Sovtek tubes in my amps, which have AC heating. The current production WE is the quietest. They have a patented method of hanging the cathode element that is supposed to make it more precisely symmetrical (not relevant to DC heating).
The japanese dont use we 300b the new ones ie . they were quite enthusiastic when they first came out but the interest petered there with takatsuki quite popular and the nos options. Its a bout reliablility of the new we 300b - they are not as reliable i understand
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