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Cool new USA based company / tube amps


joessportster

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Hi Joe,  he posted his email for you to contact him, you probably have to manually type it into the address of your email software.

 

 

 

toolshedamps@gmail.com

 

 

 

 

Matt, are your speaker amps ultra linear? And I noticed that you offer a 6W6 option for your Genesis 6 amp, does it still put out 6 watts with this tube?

Howdy, they are not Ultra-Linear, typically the 40% tap is a delete option from my OT winder. The Genesis6 is running about (trade secrets,  ;) 250v on the plate @ 40mA, CCS Bias) = Awesome! :)

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A great example of Shade feedback I see Mike. It's hard for me to see the screen hookup for the EL84's, did you use the typical 2k2 value from the plate supply?

 

 

 

I am very curious if the Renaissance amp has a similar feedback approach, or if it uses the more common global feedback around the transformer. :rolleyes:

Howdy, No this is not "Shade" feedback at all, however, it is a type of Anode to Anode feedback. And, No, it's not derived from the plate supply at all.

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The Renaissance4 uses the same tube lineup as my homebrew RH84 amplifier.

 

It isn't as fancy, but it sounds good...

 

DSCN1136.JPG

 

DSCN0993.JPG

Hi Mike, that is a very nice amp! Beautiful layout! I am a huge fan of PRP resistors, I use them on the Cathodes of my amps exclusively. Nice work!  :D

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Howdy, No this is not "Shade" feedback at all, however, it is a type of Anode to Anode feedback

 

Okay since "Schade" feedback is controversial maybe we can call it something else. Regardless it's the same thing. You say anode to anode but the 12AT7's anode is connected to the EL84's grid.......so it's plate to grid ala "Schade".

 

 

 

 

And, No, it's not derived from the plate supply at all.

 

Maybe I wasn't clear, I was speaking in regard to the screen connection of the EL84 in Mike's RH84 amp, the screen is tied to the plate via a 2k2 resistor.

Edited by xxJPMxx
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A great example of Shade feedback I see Mike. It's hard for me to see the screen hookup for the EL84's, did you use the typical 2k2 value from the plate supply?

 

Yes. You can see the one carbon composition 2.2K 1/2 watt resistor. If you follow the orange wire from behind that resistor, you can barely see the other one under the front of the output transformer on the right.

Dunno why I used a carbon comp...musta ran out of money and used what I had on hand...

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Hey Matt, you seemed to not answer my question from before. Does your Genesis 6 amp produce 6 watts at 250v and 40mA bias with a 6W6, 6V6, or 6Y6?

 

I never understood amps that are made for "tube rolling", certainly the load impedance is optimum for only one tube. Also you wouldn't want a customer to pop in a 6W6 and have it be -3db.

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Howdy,

 

Hey Matt, you seemed to not answer my question from before. Does your Genesis 6 amp produce 6 watts at 250v and 40mA bias with a 6W6, 6V6, or 6Y6?

 

I never understood amps that are made for "tube rolling", certainly the load impedance is optimum for only one tube. Also you wouldn't want a customer to pop in a 6W6 and have it be -3db.

Howdy,

 

Without going into to much detail, the MAX output of the Genesis6 using 6L6GC or KT-66's is 5.86 watts. Using the 6W6GT (my particular favorite for this operating point) yields a hair over 3.2 watts with 200v on the screen. MORE importantly, the "proof is in the pudding" so they say. 

 

As far as "not understanding" why builders allow for "tube rolling," one glance at a data sheet will show you that load impedance is not entirely a "fixed" parameter under EVERY operating condition. Most valves will function regardless of operating point provided one or more of the MAX conditions are not exceeded (or nearly exceeded for more than one parameter). Therefore, before making snap judgments based on data alone, what is necessary is "playing" with operating points to find the "sweet-spot" for a particular topology.

 

I am NOT inclined to comment on other builders' topology, methodology, parts quality, aesthetic appeal, etc., I know what works for me, and I believe that one listen would confirm what many customers (such as my last post supports) enjoy about my particular flavor. :)

 

Matt. :) 

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Very very nice build. I only wish my builds looked like yours and Maynard's. A lot of attention to layout and detail of component placement.

 

I agree, there is something beautiful about a nice symmetrical layout. And no spaghetti city of wire is nice for troubleshooting and less EMI and stray capactitance.

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Without going into to much detail, the MAX output of the Genesis6 using 6L6GC or KT-66's is 5.86 watts. Using the 6W6GT (my particular favorite for this operating point) yields a hair over 3.2 watts with 200v on the screen.

 

Well this is the place to go into detail, we like to discuss valve amps here :) I figured with the 6W6 it would be around 3 watts. It might be misleading for people not in the know to swap a tube and expect the same output power. I would probably revise your webpage with the different power output with each tube, heck maybe even add the measured distortion with each valve. Or better show a FFT so people can see the distortion spectrum.

 

 

 

MORE importantly, the "proof is in the pudding" so they say.

 

I don't like pudding can I have a cupcake?

 

 

 

one glance at a data sheet will show you that load impedance is not entirely a "fixed" parameter under EVERY operating condition.

 

I agree, but you built an amp with a fixed load impedance and a fixed operating point. The 6V6 at the same operating point will most likely have about double the plate resistance of the 6L6GC yet you give it the same load impedance. Certainly the 6V6 in that situation will most likely have a higher THD %. In short yes it will work, but it's not optimum.

 

 

 

Therefore, before making snap judgments based on data alone, what is necessary is "playing" with operating points to find the "sweet-spot" for a particular topology.

 

No snap judgement made here, you can't deny that with some plate curves and a little time you can calculate an optimum condition for a specific valve. That condition may work with other valves but maybe not as good. Also data helps to shorten the amount of time "playing" around to find the "sweet-spot". And in all honesty these tubes have been around for a long time, most of us know their sweet spots.

 

 

 

I am NOT inclined to comment on other builders' topology, methodology, parts quality, aesthetic appeal, etc., I know what works for me, and I believe that one listen would confirm what many customers (such as my last post supports) enjoy about my particular flavor.

 

You don't have to comment on others builds but we welcome it and I speak for myself in that I would appreciate it. Maynard, wdecho, and some guy thesloth had this section made for this exact purpose, to discuss tube amps and tube amp designs. The more you show your knowledge and your amps superiority the better the sales can only get.

Edited by xxJPMxx
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Howdy,

 

Hey Matt, you seemed to not answer my question from before. Does your Genesis 6 amp produce 6 watts at 250v and 40mA bias with a 6W6, 6V6, or 6Y6?

 

I never understood amps that are made for "tube rolling", certainly the load impedance is optimum for only one tube. Also you wouldn't want a customer to pop in a 6W6 and have it be -3db.

Howdy,

 

Without going into to much detail, the MAX output of the Genesis6 using 6L6GC or KT-66's is 5.86 watts. Using the 6W6GT (my particular favorite for this operating point) yields a hair over 3.2 watts with 200v on the screen. MORE importantly, the "proof is in the pudding" so they say. 

 

Matt. :)

Matt, pardon my curiosity, but have you taken any screen current measurements when zero bias is approached?  I'm a bit perplexed about running 200V on the screen, which is higher than the design-center rating, and I wonder about the screen dissipation.  Any thoughts on the longevity of the tube when running at the voltages you indicated?

 

Maynard

Edited by tube fanatic
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Whoa....apparently this forum is for armchair physicists and DIY-ers to share ideas. I build a product/s that sound awesome, look good, AND pair exceptionally well with PWK's designs.

The point is, I'm not about to discuss in detail how I manage to build an amplifier that sounds better than those available (according to the latest review) from Dennis Had, and Nelson Pass.

Simply put, I listen with my ears, not my eyes. Data Sheets are all well and good, however, in most cases they provide "suggested" operating points, which were created in a time before Teflon dielectrics, amorphous-core OT's, noiseless 1% metal-film resistors, copper foil & oil coupling caps, SAND, 24/192, etc.

The most important point is: By constantly insisting and suggesting their are "better" topologies, tubes, methodologies, etc., and THEN demanding raw data to support these positions, just simply serves to SHRINK the possible "pool" of enthusiasts who would otherwise enjoy what a tube amplifier can do for their enjoyment OF THE MUSIC.

Nuff' said

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The most important point is: By constantly insisting and suggesting their are "better" topologies, tubes, methodologies, etc., and THEN demanding raw data to support these positions, just simply serves to SHRINK the possible "pool" of enthusiasts who would otherwise enjoy what a tube amplifier can do for their enjoyment OF THE MUSIC.

 

I'm the least technical person here and most all the voltage talk is over my head however I don't see how asking you questions will shrink the pool of tube enthusiasts.  I would think just the opposite.

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  Diversity is what makes the audio hobby interesting, and, Tolerance is what makes it fun. 

 

. However, if anyone has any questions I will be happy to answer them. 

 

 

 

 

We're a very diverse and inquisitive forum.  We're glad you're tolerant and happy to answer our questions.

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Whoa....apparently this forum is for armchair physicists and DIY-ers to share ideas. I build a product/s that sound awesome, look good, AND pair exceptionally well with PWK's designs.

The point is, I'm not about to discuss in detail how I manage to build an amplifier that sounds better than those available (according to the latest review) from Dennis Had, and Nelson Pass.

Simply put, I listen with my ears, not my eyes. Data Sheets are all well and good, however, in most cases they provide "suggested" operating points, which were created in a time before Teflon dielectrics, amorphous-core OT's, noiseless 1% metal-film resistors, copper foil & oil coupling caps, SAND, 24/192, etc.

The most important point is: By constantly insisting and suggesting their are "better" topologies, tubes, methodologies, etc., and THEN demanding raw data to support these positions, just simply serves to SHRINK the possible "pool" of enthusiasts who would otherwise enjoy what a tube amplifier can do for their enjoyment OF THE MUSIC.

Nuff' said

 

 

Let's take a step back here. Nobody doubts how good your amps sound, which in my opinion is dependant more on speakers and room than amp but it's part of the equation. Also "good" sound is subjective so I try not say brand A is better than brand B.

 

Also I don't think anyone is suggesting you use a "better" topology, engineering is about trade offs and any particular topology has it's advantages and disadvantages.

 

Most of us have no problems sharing our schematics, I can call McIntosh right now and they will send me any schematic I want. I could probably reverse engineer your amp from just an under the hood picture, it's not rocket science here ;)

 

You did state if anyone has any questions that you would answer them. I guess I ask stupid questions :(

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Whoa....apparently this forum is for armchair physicists and DIY-ers to share ideas.

 

Yeah, this is a veritable hive of sweep tube ninjas you've stumbled into, they're not novices.  I think there is a shared appreciation for these devices around here, so don't bristle at friendly requests to share your approach.  If you do, I think it would only help you in the big picture.  If one amp is "better" than another is a pissing contest that should be avoided, particularly if it's based on reviews in an audio rag, and in this realm, where some wiggle room for idiosyncratic approaches should be accommodated.  I would like it if you would at least discuss what informs your taste when balancing the trade offs and compromises involved with choosing a particular design, whether that's a musical background that's trained your sensibilities, or more specifics on your amps and how they get you there, if you choose to disclose such info.  

 

All I can say is that a Dennis Had derived amp wrapped in beautiful cosmetic packaging for under a grand grabs my attention.  The defensive stance exhibited in your last post, not so much. 

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The defensive stance exhibited in your last post, not so much.

 

I am surprised to see this thread go this direction. Honestly that point Maynard made about the screen for the 6W6 is very valid for tube life, my opinion he should be thanked. The 6W6 screen is rated the lowest in terms of dissipation in the list of acceptable tubes to be used. Since we know the screen voltage is 200V then during just quiescent operation it most likely is already at 1 watt, the max rating. No biggie, those tubes are cheap ;)

 

 

 

 

 

Data Sheets are all well and good, however, in most cases they provide "suggested" operating points, which were created in a time before Teflon dielectrics, amorphous-core OT's, noiseless 1% metal-film resistors, copper foil & oil coupling caps, SAND, 24/192, etc.

 

What does Teflon dielectrics, amorphous core OT's and blah blah blah have to do with datasheet or how a tube operates? Electrically we are concerned with transconductance and plate resistance, or mu = gm * rp     Of course other parameters can't be useless like direct interelectrode capacitances and the plethora of other data included in datasheets, right? And then there is the most important part of the datasheets which are the average characteristic graphs in which you derive the gm and rp from. If I can't find these for tube I will graph them out myself or have someone use a curve tracer for me, this will help you get a good view of how linear a valve will operate. I mean who wants non linear devices?

 

Some like to design amps empirically and some do it on paper, some a little of both (most good builders). I take it you do it empirically.

Edited by xxJPMxx
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