Great. I thought N.P. said this thing was 5 bucks and available at Digi-Key...
Well, to him maybe. It's listed a $6.70 or something w/none in stock(non stocked) and a min order of 60! Oh well...
I'm deffinatly up for a handfull of those. Thx
Nelson said at BA that the IXYS thingy was about 6 bucks a pop and one of those non-stock "stock" items at Digikey with a min order of 60 pieces ( about two-three tubes worth). He flat-out recommended a group buy.
Wrenchone,
I am offering a group buy for these.
Offering another solution, you can order them from mouser individually, at a higher costs.
The group buy will take about two months from close to get delivery.
Where to find those beautiful light bulb sockets Nelson uses on this amp?
The ones on the photos linked by Steve seem to be the same...
I already checked german online stores, the nicest ones I found are those:
The ones on the photos linked by Steve seem to be the same...
I already checked german online stores, the nicest ones I found are those:
Hi,
Getting "proper" lamps in Europe should not be so difficult, but they may not look so "romantic" like the old style incandescent lamp. For example, this one can be used:
OSRAM 64701 300W 230V R7S - Licht-123 -Leuchtmittel - Strahler - LED - Osram - Philips - SLV - Paulmann - Trio - Megaman - Massive
Beware that in order to get the needed current, up to ten such lamps may need to be wired in parallel (5-10 actually, depending on the desired current). Also, a funny idea would be to build an amp which would actually look like a small stove. (actually an amp inside a small stove). Or, an amp with a pair of water kettles on top, like this: Amazon.com: Aroma AWK-115S 1-1/2-Liter Hot H20 X-PressWater Kettle: Kitchen & Dining (they will have be filled with a bit of water, which will get warm during operation) 🙂
On the other hand, its is known that Nelson uses a lighbulb as a CCS in his tutorial examples. So, we may be looking toward another depletion mode mosfet on top as a CCS. Then, let's revise most of the ZEN series (1-7)...I think that SOZ with the Ixys device would be cool (hot actually) 😎
Getting "proper" lamps in Europe should not be so difficult, but they may not look so "romantic" like the old style incandescent lamp. For example, this one can be used:
OSRAM 64701 300W 230V R7S - Licht-123 -Leuchtmittel - Strahler - LED - Osram - Philips - SLV - Paulmann - Trio - Megaman - Massive
Beware that in order to get the needed current, up to ten such lamps may need to be wired in parallel (5-10 actually, depending on the desired current). Also, a funny idea would be to build an amp which would actually look like a small stove. (actually an amp inside a small stove). Or, an amp with a pair of water kettles on top, like this: Amazon.com: Aroma AWK-115S 1-1/2-Liter Hot H20 X-PressWater Kettle: Kitchen & Dining (they will have be filled with a bit of water, which will get warm during operation) 🙂
On the other hand, its is known that Nelson uses a lighbulb as a CCS in his tutorial examples. So, we may be looking toward another depletion mode mosfet on top as a CCS. Then, let's revise most of the ZEN series (1-7)...I think that SOZ with the Ixys device would be cool (hot actually) 😎
Will you be able to take 30? If so, we can share a batch of 60 as we are both in Bay Area. I can hand delivery 🙂
PM me if interested.
Hola Hombres,
Back In the 60's and 70's some chrysler autos used ballast resistors in the 12V primary side of the ignition coil circuit(readily available maybe a source to be checked out ((beefy thing in ceramic and nichrome assy's))...
Just a thought..
Dreaming In SC, Elwood
Back In the 60's and 70's some chrysler autos used ballast resistors in the 12V primary side of the ignition coil circuit(readily available maybe a source to be checked out ((beefy thing in ceramic and nichrome assy's))...
Just a thought..
Dreaming In SC, Elwood
Can anyone provide a more legible drawing of this amp -- that is if Nelson would not object -- with a few resistor and capacitor suggestions scribbled in.
This build it on the kitchen table type thing is something I can get behind. Nice handwarmer with sound for the cold winter months. I have some of those old 300 watt bulbs lurking in the basement somewhere.
I guess a pair of Lowthers or Fostex high efficiency speakers are mandatory here.
Tad
This build it on the kitchen table type thing is something I can get behind. Nice handwarmer with sound for the cold winter months. I have some of those old 300 watt bulbs lurking in the basement somewhere.
I guess a pair of Lowthers or Fostex high efficiency speakers are mandatory here.
Tad
very nice idea. Also helpful it could be to use the heater of the russian power triode 6C33C (faulty exemplares of course). The triode from some commercial tube otl power amps like Graaf GM20 (GM-20)
I am not shure, whether is is really possible but for other members it is easy to find out.
I think, there are many faulty exemplares by the regarded service departments and the main reason for the not correct function are not the headers itself.
photos of this triodes you are find about
http://www.stateofgrace.net/lj/robs04180924.jpg
http://de.geocities.com/peter_rehkop/tube.jpg and
http://www.diyaudio.com/forums/tubes-valves/142528-graaf-gm20-mods-help-3.html
I measure by each heater coil approximately 1 ohms at could condition (two heater coils in one 6C33C) for 24 V I must connect 4 pieces serial (and a second group of this one parallel, if I want twice the idle current)
But as mentioned earlier, I do not know if we can do that - only an idea or thought-provoking
Excuse my ignorance, how come no resistor from G-D? Looks familiar to the one found in the beginning of the F5 article.
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Excuse my newbie ignorance, but doesn't a mosfet need close to rail voltage at input to achieve full operation. There is no voltage amplification.
Tad
Tad
As Zen Mod said, the difference is due to the Enhacement mode device and the depletion mode device characteristics. The Pic you show uses the 'ol standby enhacement mode device. It needs about 4V G-S to turn on to some idle current. The G-D R and the G-Gnd R create a voltage devider which provides about that level at the gate node.
The IXYS Depletion mode device would be on with a few amps flowing through it without any bias at all. The G-D R is not needed. In fact almost no bias voltage at the gate is needed. It just so happens this device will provide a reasonable idle current with the Gate at about Gnd potential. Much like JFETs.
Now I want to ask a question. 🙂 The 10k R from G-S is a little interesting. I haven't given it enough thought yet obviously but it does more than give the amp an input resistance. It is tied to the Source R which will create some Positive feedback 😕 Is this one of those distortion cancelling methods?