What kind of bass? Musicman made some series with a switchable parallel/series humbucker for tonal variaty.
1r in a 20V winding?
Maybe, why not?
1R in a 400V winding?
Nonsense, absolutely impossible.
Current peaks 400A out of a HV winding of a tube amp transformer?
Nonsense, absolutely impossible.
Anybody who actually measured a tube amp PT would know that they are usually around 20 to 40 ohms, and *much* more so in a small (preamp only) PT.
I wouldn't be surprised to find 200 ohms and even more in JFace's transformer HV winding.
I always like to refer to *real* amplifiers, made and sold commercially, because that's the "real World", like it or not.
Something only the NASA might have or what a rich DIYer made out of Unobtainium , spending thousands of U$$, may be an interesting side note but not available to the "normal" DIYer which I always try to help.
Some real world examples:
very few makers state the DC resistance of their transformers in their schematics.
One which does is Silvertone.
Won't post the full image here to avoid cluttering the page, but for those who want to check:
Silvertone 2 x 6V6 = 35+39 ohms http://www.users.qwest.net/~ptaylor/Audio/6V6PPamp/Tube_Amp_Schematic.gif
Silvertone 4 x 6L6= 24+24 ohms http://www.reocities.com/bobdanielak/1474Schem.jpg
1 ohm? ......... not even close !!!!!
NO!!! but ... YES!!!!
Thanks anyway, for agreeing that solid state can *easily* be *a lot* less noisy than tubes.
Exactly what the salty posts above had said, by the way
So you intend to sell your products by bashing respected producers.
I think this is wrong under Forum rules.
Peavey uses the best commercially available parts, including metal film resistors.
Besides that, they are famous for their reliability.
Soldano IS a "Boutique" Amp maker by any definition of the word.
NO .... WAY ...
The first 3 triodes are very similar in both, BUT
a) the Soldano has THREE gain stages (plus a pre clipper)
b) the 5150 has FIVE gain stages (plus a pre clipper), which account for the monster gain .... and the monster hiss.
besides :
Soldano drives the Tone Control from a cathode follower
Peavey drives the Tone Control from a tube plate ... very different.
To show this clearly, even to the relatively unexperienced reading schematics:
Soldano SLO (3 gain stages)
An externally hosted image should be here but it was not working when we last tested it.
Peavey 5150 (5 gain stages)
Sorry if it's much wider than the SLO schematic, but it happens to have, huh .... 2 more stages
An externally hosted image should be here but it was not working when we last tested it.
Note: SLO *appears* to have an additional gain stage/cathode follower, but see that signal sent to it is padded around 50X, same as stage gain, so I behaves as a "unity gain block.
More important: it contributes nothing to gain or distortion, it was added so high signal levels common in tube preamps can be interfaced to standard SS effects, without clipping them to death .... what I commented in post #29 .
Bashing again the competition, huh?
What's behind this?
Oh, NOW I see it.
Personally I believe in helping fellow Forum Members without asking $$$, you try to sell books. Oh well.
Bashing again the competition, huh? <-- this is becoming repetitive.
Yes, they noticed problems after a ton of amps were sold, so the noise gate was added to a later version ... and of course can (and should) be retrofitted to 5150 .
I am explaining tube noise, showing examples where it hurts , and showing some solutions.
Very relevant to what is being discussed here, specially because there will not be much new from the OP until he actually builds the preamp and posts it here, so ...
And I think this noise discussion is important for many Forum members, specially because it shows what can and what can not be done about noise, and what realistic results to expect.
Maybe I'm an old style Pro, but I don't call people "the dude".
Even less in a Public Forum.
FWIW Peavey, Soldano and a ton others do use MF
This continued bashing is going way beyond Ethics.
FWIW I NEVER bash "competition" to boost my sales, first of all on principle and second, because it backfires, creates bad Karma and lowers your credibility.
110% Marketing.
What is this doing here?
Isn't there a Forum section for Commercial Vendors?
Hi Guys
Fahey, you are all off topic again.
Poor JFace must be completely confused by your ramblings, were they only factual...
JFace, I encourage you again to build this preamp incrementally. You should not expect to jump directly to a finished product in one step - unless you have a lot of experience. The circuits being discussed are simple, so hand-wiring a couple of sockets is no big deal.
Begin with a two-stage circuit with EQ and level in between, and an output level driving a buffer. You will likely be surprised at how close this comes to fulfilling your tonal requirements. There is still one triode left unused to add in for more colour or active EQ, whatever you decide you want to try next or think will fill any useful hole in tone or features.
None of this is rocket science. Tubes are very forgiving and electrically tough. For example, if you inadvertently swap the plate and cathode Rs, the sound will just be low in level and gain. Swap them to their intended places and everything comes to life.
Have fun
Kevin O'Connor
Fahey, you are all off topic again.
Poor JFace must be completely confused by your ramblings, were they only factual...
JFace, I encourage you again to build this preamp incrementally. You should not expect to jump directly to a finished product in one step - unless you have a lot of experience. The circuits being discussed are simple, so hand-wiring a couple of sockets is no big deal.
Begin with a two-stage circuit with EQ and level in between, and an output level driving a buffer. You will likely be surprised at how close this comes to fulfilling your tonal requirements. There is still one triode left unused to add in for more colour or active EQ, whatever you decide you want to try next or think will fill any useful hole in tone or features.
None of this is rocket science. Tubes are very forgiving and electrically tough. For example, if you inadvertently swap the plate and cathode Rs, the sound will just be low in level and gain. Swap them to their intended places and everything comes to life.
Have fun
Kevin O'Connor
Hi Guys
JFace, in general there is no issue with switching values of cathode bias for a preamp or power tube.
The drawing you posted does not show a means to actually bias the tube. If the grid-stop is tied to a volume control wiper or something referenced to ground, then your follower circuit won't be very linear regardless of Rk's value. If the invisible grid-leak is tied to a voltage reference, then the only thing that will happen as you change Rk is that the tube will conduct more or less current at idle, being able to drive lower or higher load impedances as it is switched. Tonally, there will be no difference.
Were you to change Rk in a gain stage, you would be changing gain and the distortion characteristic of the output.
If you were changing Rk in a power tube - yes, we know this is a preamp but you can use power tubes as voltage amplifiers, too - then you change the idle current and the class-A region, and power output.
Note that a second way to wire the switch is with all Rs in series, shunting out the portion of the string you don't need. Either way, this or what you drew, will provide a high Rk during the switch motion, briefly setting the tube to a low current and reducing thumps.
Have fun
Kevin O'Connor
JFace, in general there is no issue with switching values of cathode bias for a preamp or power tube.
The drawing you posted does not show a means to actually bias the tube. If the grid-stop is tied to a volume control wiper or something referenced to ground, then your follower circuit won't be very linear regardless of Rk's value. If the invisible grid-leak is tied to a voltage reference, then the only thing that will happen as you change Rk is that the tube will conduct more or less current at idle, being able to drive lower or higher load impedances as it is switched. Tonally, there will be no difference.
Were you to change Rk in a gain stage, you would be changing gain and the distortion characteristic of the output.
If you were changing Rk in a power tube - yes, we know this is a preamp but you can use power tubes as voltage amplifiers, too - then you change the idle current and the class-A region, and power output.
Note that a second way to wire the switch is with all Rs in series, shunting out the portion of the string you don't need. Either way, this or what you drew, will provide a high Rk during the switch motion, briefly setting the tube to a low current and reducing thumps.
Have fun
Kevin O'Connor
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