Dave Funk's Tube Amp School

[grangeramp]

Wanna put this "discussion" about power cords to rest? Play your guitar through your favorite amp for a few minutes. Then switch off your amp, go turn off the breaker to your wall outlet, take the plate off your wall plug, and wire your amp straight up to the wall wiring. Solder the solid wire straight to the AC inlet wiring. Flip the breaker, fire up your amp. Hear any difference?

If a power cable colors sound, then theoretically, wiring an audio device straight to the wall wiring should be the most uncolored sound of all correct?

[Allynmey]

I would like to interject here. This isn't Harmony Central

Please keep the comments civil. In my circles, and many others, Dave is a respected amp tech and beyond. I for one, appreciate him contributing to the site. I think he was treated rudely when he first posted. A simple PM to the mods from anyone asking his original thread be moved to the For Sale Forum would have sufficed. I don't want this forum to end up like 18watt.com where all the experienced builders left due to being shit on by people with no respect for the guys that started the forum or built good reputations in the industry.

My apologies Dave.

Allyn

[Thunderfunk]

I can really see a need for a power cord that can deliver a lot of clean power to an amp, as long as that amp was in need of a lot of power (Current/voltage) like a 1000 watt PA amp that was driving a lot of bass, but please explain to me how a ac circuit capable of delivering 20 amps at the outlet would have a problem supplying a couple of amps to my 35 watt guitar amp through a 16 gage line cord.

You didn't read the White Paper. It's not the amount of power delivered to a high current amp. People constantly think it's a question of Current Capacity. I'd say it's more like resonance. You're adding an 8 foot antenna onto your transformer. Sometimes you pick up RF into your amp and it comes in on the iAC cable. You go to Radio Shack and get a $5 ferrite bead and clamp it onto the cable. It blocks high frequencies. Now, how does THAT work? You've probablty even seen these heavy things on wall wart wires for video cameras.

http://www.radioshack.com/product/index ... Id=2103222

How does it work? Simple. Inductance blocks high frequencies. So now you see that the resonacne of (on) the cable can affect it's frequency response, and that the RF that's been removed was a part of the signal the cable was carrying. So the cable affects frequency response by it's resonance. You do know that all the output signal goes through the power transformer and the cord is attached to the transformer leads? It has little to do with the current draw.

...if you expect to come here and throw out "Endorsments" like that and not have any one question the validity of your statements as fact, then we wouldn't have much of a forum.

Excuse me? Throwing around endorsements? I'm not asking you to believe me. I'm just giving you a heads up for what works out there. Something you guys asked me to do as "payment" for playing in your sandbox. Now you don't like the message so you attack me? Check it out. If you can't hear the difference, don't spend the money. What's the problem with you guys understanding that? If you think I'm saying, "Close your minds and follow what I say" then you're not getting it. If you CAN hear the difference, then I don't have to tell you to buy it. You will. If you think ESP is paying all these endorsers to lie, then you're just paranoid, and you shouldn't leave the house.

Now you're also assuming that all these readers have ears. Sorry. That's a skill that takes years to develop. Without ears, you can't come close to building a Trainwreck. It's not a mechanical process of this part connected like this, with this lead dress. How do you pick the tubes? And you want me to believe that YOU can hear the difference between tubes, but all power cords just sound the same? Doesn't THAT seem strange to you? A tube is just an electro-mechanical device. Maybe if Michael puts "Mullard" on the power cord? Feel better?

Dave

PS, Thanks Allyn.

[bnwitt]

Please keep the comments civil. In my circles, and many others, Dave is a respected amp tech and beyond. I for one, appreciate him contributing to the site. I think he was treated rudely when he first posted. My apologies Dave.
Allyn

Oh come now Allyn. If he wasn't a friend of yours (or someone who has a perceived value to you) we wouldn't be having this discussion. A total stranger who lurked for a year and then made a first post to sell something would have been toasted as always. But he's your buddy so I'm rude huh? I think I'll just take my honesty somewhere else sport. You stopped sharing information in here a long time ago anyway. I guess business is good. Adios fellows.

[j-po]

I guess they are pleased you're leaving. Easier to sell hocus-pocus to newbies like me after you're gone.

[rhinson]

[/quote]

Describe the sound? More "real?" For those who don't know I'm building a bass amp that's knocking off the big boys. Last year I changed the first chip in the signal chain from an opamp to a preamp. Until this proprietary chip was available you had nothing to compare it too. Opamp to opamp still sounded like an opamp. Some better or worse. But when you can compare an opamp to a PREamp, then you hear what was missing all along. until then, you didn't know. How would you? There was nothing to compare it too.




Dave[/quote]

hey dave, i've never heard of this particular type of ic. do you have a link to the company that makes them? i'd like to look at a datasheet and see how the internal generic schematic compares to the standard single/dual opamps we all see in pedals, guitar amps, etc. thanks rh

[rooster]

Dave - Hey, thanks for addressing my questions and issues - and doing a very good job of it, too. I hope you do post a few things from time to time, as well.

As to cables, I am open to all of it actually and I don't believe in Aliens either. I am using Evidence Audio cable and I do understand what you meant when you said you need an educated ear to hear some things. I love this stuff and I can blind test it, too. Funny thing is, after most people switch back and forth a few times with 'other' gtr cables, they can do this too. But like you say you have to experience it first.

Anyway, eh, come back. Oh, BTW, that youtube video you mentioned with Glen? That was biased at 45ma as far as I know, and probably not Mullards or Telefunkins? Glen? But no matter, you are right about the harmonic context thing, it exists, there it is. Beautiful Tone!! Ken was a mfr in this department. Take care.

[j-po]

It's not the amount of power delivered to a high current amp. People constantly think it's a question of Current Capacity. I'd say it's more like resonance. You're adding an 8 foot antenna onto your transformer. Sometimes you pick up RF into your amp and it comes in on the iAC cable. You go to Radio Shack and get a $5 ferrite bead and clamp it onto the cable. It blocks high frequencies. Now, how does THAT work? You've probablty even seen these heavy things on wall wart wires for video cameras.

Talk about RF blocking inductance - isn't there plenty of inductance in the power transformer to block a few mV of RF? I can't see how a power cord or ferrite bead would do anything here. Nor have I seen ferrite beads on AC wires of any video cameras. Even if such had been done it surely would be more effective to put the bead on the dc side rather than ac of the transformer, like a choke in an amp...

Another point is that for the power cord to be able to act as an antenna I would have though the wall socket would have to present a very large output impedance which surely is not the case.

Maybe I should join your tube amp classes to learn more of this stuff.

[Fischerman]

The Amp Garage
A tube amp builder's community

If you could tell us how to DIY our own uber power cord for a fraction of $180 then that imo would be more in the spirit of the forum. IMO.

EDIT: By the way Dave...I bought a 'leftover' Climax 2x10" (Vibrolux Reverb) cabinet in the late 90s I think. If this cabinet is anything like any 'production' Climax cab then I know at least one reason why they didn't sound that good. This cabinet sounds pretty dead and eats power like nothing I've ever had.

[Structo]

Well sorry if I came off brutally skeptical.

Those types of things might thrlll the Hi Fi crowd but generally I think guitarists that use vacuum tubes are naturally a bit skeptical.

Whenever I see claims like the MusicCord makes I am reminded of the blind test where bunch of speaker cables were tested. From zip cord on up to the very spendy silver coated, oxygen free, multi conductor, Low Z, blah blah blah cables.

What the listeners didn't know was that the guy demonstrating the cables at one point substituted ordinary wire coat hangers for cables at one point.

Which cable did the critically listening group pick as the most transparent, least coloring, best fidelity cables?

You guessed it. The coat hangers.

Or the wooden Hi Fi knobs that cost $350 each which will make any Hi Fi sound better.

Had Dave came here and said Hi boys hows it going and participated for a few days or weeks before advertising an amp school in the Trainwreck section people might have warmed up to him. Instead his first post was about an amp camp and I see his post has now been edited.
Then 4 days later advertise for ESP power cords, I can see where it might ruffle a few feathers.

For shielded signal carrying cables I do know and have heard first hand what a better cable sounds like.

But like Dana said, you are going to use a six foot piece of wire to go from the amp to a wall receptacle that is wired to hundreds of feet of AC wiring in your house, which is then connected to a transformer which is connected to a network of AC wiring in your neighborhood.
From the IEC connector to your transformer and power supply.
I see a far better use of a EMI filter on the IEC or even a power conditioner that filters and regulates the wall voltage. But even those are priced very high for what usually amounts to a few thermisters.

I don't own Mr. Funks book and will probably never buy it as I can glean a lot of info for free on the net.

I notice that when he dangles a carrot in front of a bunch of guys in the Trainwreck section who love those amps the same way some of us love the Dumble thing, he says he can't or won't divulge the answer or little known tidbit that a handful of home builders would like to know.

Dave is probably a nice guy with a tremendous amount of knowledge, but all I know if anybody else had came here and there first post was to sell something without so much as an introduction they would have blasted much like Dave was.
And why didn't he post it in the For Sale section?
He then could have introduced himself in any section he wanted and referred the guys to his ad.
Or god forbid, offer some insights to the mysterious wreck amps that a few guys are so engendered with that they cobble together one for themselves.

[UR12]

You didn't read the White Paper. It's not the amount of power delivered to a high current amp. People constantly think it's a question of Current Capacity. I'd say it's more like resonance. You're adding an 8 foot antenna onto your transformer. Sometimes you pick up RF into your amp and it comes in on the AC cable. You go to Radio Shack and get a $5 ferrite bead and clamp it onto the cable. It blocks high frequencies. Now, how does THAT work? You've probablty even seen these heavy things on wall wart wires for video cameras.

You are right I didn’t read the white paper. I actually tried one of these power cables on a Guitar amp , (not a mixing board, bass amp or Sound system) and formed my own opinion. Isn’t that a strange approach? (Maybe we weren’t close enough to a radio station). We actually had 5 or six guys try it and came to the same conclusion, so I guess we’re all deaf no talent bum amp builders compared to some of the Gods around here who were born with golden ears. The last time I bought a product by reading a white paper I was also disappointed. According to the clinical studies cited in the white paper my male member should have been 12 inches long in only a few months. It didn’t work either and then the food and drug administration did their own study and found the white paper to have a few inaccuracies in it. (More advertising than fact) I have since decided that anything I read on the internet has got to be true because I don’t trust the food and drug administration either.

Now you're also assuming that all these readers have ears. Sorry. That's a skill that takes years to develop. Without ears, you can't come close to building a Trainwreck. It's not a mechanical process of this part connected like this, with this lead dress. How do you pick the tubes? And you want me to believe that YOU can hear the difference between tubes, but all power cords just sound the same? Doesn't THAT seem strange to you? A tube is just an electro-mechanical device. Maybe if Michael puts "Mullard" on the power cord? Feel better?

I am not assuming anything. I am stating my direct experience with the product, just like you did. Your take is that if someone can’t hear a difference then there must be something wrong with our hearing and not the product. Unless they have a birth defect or have had their ears amputated, yes I believe that 99.9% of the people who enjoy playing and listening to music have ears. I have a few Mullards lying around that sound like crap. Some of them hiss, some of them hum, some of them whistle, some of them squeal and some of them sound great. I can hear all of those things with my less than perfect ears and I don’t recall ever asking myself , “I wonder what Dave Funk believes?”.

So based on your conclusions, we are all wasting our time. We should just shut down the forum because all of us here have it wrong, we will never be able to “come close to building a Trainwreck” sounding amp. We have all heard that so much over the years that you would think we would have quit even trying by now. But thank you just the same for the free lecture.

[Voodoo_Man]

You didn't read the White Paper. It's not the amount of power delivered to a high current amp. People constantly think it's a question of Current Capacity. I'd say it's more like resonance. You're adding an 8 foot antenna onto your transformer. Sometimes you pick up RF into your amp and it comes in on the iAC cable. You go to Radio Shack and get a $5 ferrite bead and clamp it onto the cable. It blocks high frequencies. Now, how does THAT work? You've probablty even seen these heavy things on wall wart wires for video cameras.

http://www.radioshack.com/product/index ... Id=2103222

I took the ferrite bead/clamp from the power cord of my DVR and put it around one of my amps power cord and it didn't seem to attenuate any high frequencies or produce more clarity. Amp sounds the same with or without. Do I need the one from Radio Shack or what?

God Bless,
John

[rawnster]

How would this power cable work in a real world gigging situation? Most venues require a long extension chord to get power to the amp. Most extension chords are 18 gauge. Then there's probably a powerstrip of some kind at the end of the extension chord to divy up the power to all the other toys needing AC. Wouldn't the extension chord cancel out most of the positive benefits found in the superior power cable?

Just a question...

I can see where this chord may work well in a controlled studio/home environment; but down at the local Starbucks....I'm not sure.

[Tubetwang]

out of curiosity...i looked them up and Elevators are still around...

http://www.musicdirect.com/product/73452


Like i said...try before you buy or make certain you can send them back for a FULL refund if your not satisfied...Nothing like experience...

[Structo]

Now I know why they call them audiofools.