Hi,
The tubes on my Melody i880 amp need to be replaced. The amp uses one 101D vacuum tube that seems to be pretty rare and 'expensive'. Can I replace this tube with alternative tube?
If not, any suggestions to were to find a budget 101D?
Thank you,
Jock
The tubes on my Melody i880 amp need to be replaced. The amp uses one 101D vacuum tube that seems to be pretty rare and 'expensive'. Can I replace this tube with alternative tube?
If not, any suggestions to were to find a budget 101D?
Thank you,
Jock
You should probably have them tested to be sure. Some of the old, directly heated tubes had a fairly long life compared to, power tubes. Does anyone know what the 101D tube does in this amplifier?
It seems to only have one so it could not be the input stage for a stereo amplifier.
It seems to only have one so it could not be the input stage for a stereo amplifier.
Full Music and Psvane make 101D replicas, probably a good place to start. There are probably be others. Make sure that you get ones that have the correct pins for the socket in your amp and the correct filament voltage which should be 4.5V..
Could it be that the 101D is a weird decoration gag here? I could imagine a single pentode to be part of an error amplifier to regulate B+ but have no idea how to do something like this with a 101D. Also for the price of the amplifier it most certainly is a chinese copy.
Jockaruba, out of curiousity, could you post a picture of the innards of the amp?
Jockaruba, out of curiousity, could you post a picture of the innards of the amp?
Hi Kaputt,
Please take a look at the link below at the bottom of the page:
6moons audio reviews: Melody I2A3
It 'explaines' the purpose of the 101D. I am sure you will understand (not me)
If not I can open it up and take a picture
Jock
Please take a look at the link below at the bottom of the page:
6moons audio reviews: Melody I2A3
It 'explaines' the purpose of the 101D. I am sure you will understand (not me)
If not I can open it up and take a picture
Jock
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It appears that it is used in power supply regulation. Since it is a rare tube, it undoubtedly imparts some sort of magic mojo to the power supply circuit that no other less expensive tube could.
I read somewhere (don't remember where) that the tubes it came with were supplied by full music? so that makes them a little more affordable than the 'real' thing
As the 101D is such a weedy (Ia max 12mA), low gain (mu 6, gm 1mA/V), thirsty (heater 4.5W) triode I can only imagine that either the regulator has a very peculiar circuit or the 101D is there for marketing purposes.SpreadSpectrum said:
Yes, it clarifies that the 101D appears to be a particularly poor engineering choice for that circuit function. In fact, any directly heated valve would be a poor choice when fed with AC for the filament, as that circuit does. For a good CF you need a higher gain valve, perhaps one designed for the function of pass valve in a PSU; cheap and boring. It would be interesting to hear some comments from the circuit designer.
I can't see the 101D in the schematic. The pass tube is a 300B.
My own experience of Melody is one of: style over substance.
My own experience of Melody is one of: style over substance.
mosfet or tetrode would give better results.
dht is better for sound amplification
http://www.tubecollectors.org/we/archives/101d.pdf
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