2bamp-
I just tested my new RH84 with audio from my phone's headphone out first and the volume was underwhelming. Plugged into my computer, I get way more. I haven't plugged it into a proper 2V source yet, but I bet it will be pretty consistent with other 5W amps I've used. Get thee a preamp (or a 2V source)!
Soda
I just tested my new RH84 with audio from my phone's headphone out first and the volume was underwhelming. Plugged into my computer, I get way more. I haven't plugged it into a proper 2V source yet, but I bet it will be pretty consistent with other 5W amps I've used. Get thee a preamp (or a 2V source)!
Soda
I have found the same thing. Using my netbook as a source gives way better results. In fact, I am pretty happy with it, and since I almost exclusively use my tablet, I am also glad to have a use for some more "osbsolete" electronics. Next one will get an additional gain stage.
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I have always found that it makes sense to build it as the designer originally intended and then modify after that if we can define a specific "problem". Mr. Kitic does answer emails promptly and is a big help when tackling the RH projects.
I just finished a RH307A and there is nothing that I think needs changing. An iPod is "enough" but the DAC from my "big" stereo has a lot more grunt.
According to Alex Kitic, 1V input normally drives his amps to full power. You can check your players spec to see what it needs. I would not change the feedback. Many MP3 players have limited output to prevent deafness.
The comment about it being "Schade" is not correct. They do have a similar feedback arrangement, but similar is not the same.
Changing the 12AT7 to a 12AX7 will not work. The same holds true for a 12AU7. Mr. Kitic explains why at his blog. I have no difference in gain with a 6201 or 12AT7.
My next amp is probably a RH84 to complement the RH307A Super in a triamp situation. It will drive horns.
I just finished a RH307A and there is nothing that I think needs changing. An iPod is "enough" but the DAC from my "big" stereo has a lot more grunt.
According to Alex Kitic, 1V input normally drives his amps to full power. You can check your players spec to see what it needs. I would not change the feedback. Many MP3 players have limited output to prevent deafness.
The comment about it being "Schade" is not correct. They do have a similar feedback arrangement, but similar is not the same.
Changing the 12AT7 to a 12AX7 will not work. The same holds true for a 12AU7. Mr. Kitic explains why at his blog. I have no difference in gain with a 6201 or 12AT7.
My next amp is probably a RH84 to complement the RH307A Super in a triamp situation. It will drive horns.
???
Considering the remarkable sound quality, maybe "poor" is a less applicable description.
I do not consider all anode/anode feedback to qualify as Schade. Granted, we do stand on the shoulders of giants........regardless of what we implement in tubes.
Considering the remarkable sound quality, maybe "poor" is a less applicable description.
I do not consider all anode/anode feedback to qualify as Schade. Granted, we do stand on the shoulders of giants........regardless of what we implement in tubes.
The difference you suggest is at DC and not at AC so I do not share your analysis of how it effects the AC signal. Current is the force into the relevant node (here the grid) and is dependant on the effective impedance of that node. If it is low impedance node then it will have a current character. This is the case in the Schade arrangement.
With a driver tube the function of it in AC is to present a rather fixed voltage divider feedback path to ground and the AC signal thus reduced is presented straight to the output tube grid. This is why it is a gross mistake to use a triode which has a variable impedance and hence varies the feedback applied.
I emphasis - for the AC signal the two arrangements you describe are effectively one in the same - which is what we are interested in here.
Shoog
With a driver tube the function of it in AC is to present a rather fixed voltage divider feedback path to ground and the AC signal thus reduced is presented straight to the output tube grid. This is why it is a gross mistake to use a triode which has a variable impedance and hence varies the feedback applied.
I emphasis - for the AC signal the two arrangements you describe are effectively one in the same - which is what we are interested in here.
Shoog
So, this SW I recently saw might be a product of variable feedback?
RH84, 4 ohm load.
An externally hosted image should be here but it was not working when we last tested it.
RH84, 4 ohm load.
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Where is the variable feedback in RH84? What's the input used (level and frequency)?
I think he is referring to the variable voltage divider created by using a variable impedance triode as the driver.
Shoog
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