shellylh

New Pete Millett/TTVJ amp - Apex Teton

63 posts in this topic

The heatsink is for the cathode resistors that set the current through the output tube, IIRC.  If you look at the PCB you'll see two gold-colored, 50W (I think) resistors mounted to the bottom of that sink.  I did a similar thing on the Menace.  .

 

medium.jpg

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im sure nate remembers..i spent a lot of time in 2006 or 2007 working on something like this, but never took it to production. just didnt think anyone would be willing to pay for it being done the right way when the hot thing at the time was $300 versions from China. times have changed though!

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Time to dig up that old project again??

 

Anyways, the layout (and symmetry in particular) really has nothing to do with aesthetics. It's all about fit and finish.

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I remember Tyll posting on HF around that same timeframe (2007) about an HA-2 based amp that Headroom was planning.

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For those who don't want to read the HF thread:

 

Quote:
Originally Posted by pmillett go_quote.gif

The Teton has a highish output impedance similar to the original HA-2.  The Zout depends on what output tube you use...if I recall correctly it's around 100 ohms using a 6080, and as low as 50 ohms using a 6528.

 

Of course, the output impedance affects the sound, depending on what headphones you use.

 

I also added an "IEM" mode that trades gain for output impedance, so you can drive 16 ohm IEMs.  This is done with a simple resistive alternator, no magic.  So the gain is dropped by ~15dB, and Zout is lowered to ~10 ohms.

 

Although many would argue this amp is only good for higher impedance headphones (over 150 ohms), personally I find many lower-impedance phones (like Grados) sound better with a higher source impedance.  It depends on your taste.

 

Pete

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im sure nate remembers..i spent a lot of time in 2006 or 2007 working on something like this, but never took it to production. just didnt think anyone would be willing to pay for it being done the right way when the hot thing at the time was $300 versions from China. times have changed though!

 

I believe that I have a prototype PCB tucked away in a drawer somewhere for the amp section. :)  Hopefully this will drive tube prices in a direction that allows you to think about selling some of your 421A collection. 

 

And I still think that the way to bring this type of amp to market is to do it like the TTVJ 307A and trafo couple the inputs and outputs and call it balanced.  Yes, it adds cost but the additional market created is worthwhile.  I also loved the Menace TC and if time/money permited it'd be the version that I'd build again with premium parts.  That was kind of where the thought process for Frankstein started...

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i still have all of the 6AS7, 6080, 6528, 5998, and 421A tubes that i bought.  the last version i prototyped was a transformer output version, thinking that it would differentiate it from all of the cheap OTL amps with those tubes that had flooded the market - and that i would have to acquire WE 421A tubes to ship with the amp. its still in my storage unit on a piece of wood

Edited by justin

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I was making a joke about the weight distribution

I think we all understood that it was a rhetorical question, even those of us who don't know you in person.

 

I love this place, sometimes you all have my sense of humor (or perhaps, mine is suddenly sympatico with all of yours).

 

I was also going to point out the comparison with the Wheatfield HA-2, which was downright disturbing to hold in one's hands (due to its leanings).

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And I still think that the way to bring this type of amp to market is to do it like the TTVJ 307A and trafo couple the inputs and outputs and call it balanced.  Yes, it adds cost but the additional market created is worthwhile.  I also loved the Menace TC and if time/money permited it'd be the version that I'd build again with premium parts.  That was kind of where the thought process for Frankstein started...

 

That would be a plan.  A lot of high end studio gear is single ended with transformers on each end so this makes sense.  Same reason the ECP L-2 should have an XLR output, we now the difference but 95% of HF have no clue. 

 

I'd love to take that amp apart and show how 5K$ amps should be built. 

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I'd love to take that amp apart and show how 5K$ amps should be built. 

 

I'm curious what you meant by this comment?  Based on what I see I'm not sure I'd change a thing about how that is built other than a different style of heatsink.

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^I think he probably meant that he'd like to show how well this amp is built, in contrast to certain other headphone amps that have recently been taken apart. 

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Exactly.  This is how it should be done.  Just look at the parts used in that thing, 3 transformers!!  :)

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I think it's 2 trafos and 3 chokes, but I could have that backwards.

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One standby trafo on the PCB too. 

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two transformers topside

one transformer on the bottom (blue thing)

2 chokes (E/I core black things)

2 large poly caps (white/silver things)

2 power resistors (gold things)

Edited by kevin gilmore
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$5k is a bit excessive on amp like this (looks perspective point). 

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$5k is a bit excessive on amp like this (looks perspective point).

Please, elaborate on your vast experience designing, building and distributing high-end electronics.
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$5k is a bit excessive on amp like this (looks perspective point). 

 

WRONG.  This thing looks FUCKING BADASS.  You go ahead and buy the SissyPantz BJ1 (with DAC!) for $299.95.

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:sherwood:  SissyPantz BJ1 (with DAC!)TM   :sherwood: 

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Please, elaborate on your vast experience designing, building and distributing high-end electronics.

 

I meant aesthetics wise it looks kind of plain jane. No offense or anything it's got the plain jane look similar to the ALO Studio 6. I want more bling like BHSE level. I do own and like the low-end Jonokuchi so I don't have anything against Pete Millet's designs/amps.

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I meant aesthetics wise it looks kind of plain jane. No offense or anything it's got the plain jane look similar to the ALO Studio 6. I want more bling like BHSE level. I do own and like the low-end Jonokuchi so I don't have anything against Pete Millet's designs/amps.

 

I would agree 

However; I would not call the BHSE bling as such, as it uses uses materials in a way which makes it look solid, well finished, there has been considerable thought given to to overall design and attention to detail.

 

The EAR HP4 is much more "Blingy" with all the polished chrome and gold plated knobs 

Edited by complin

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Given the cell-phone level of pictures being provided so far I think it's a little early to make sweeping generalizations about how it'll look in the flesh.  I'll grant you that it's never going to be flashy but it maintains the same general aesthetic approach of the other Apex offerings (Peak, Pinnacle, etc.) so there's good reason for it to look the way that it does. 

 

And Kevin, I think that one of the top mounted bits is a large, first stage choke.  The power supply on this thing is going to be running pretty at pretty high currents (compared to normal tube gear) ~200mA so the first stage choke would need to be a lot larger than the little guys inside the chassis.  I'm basing this assumption partially off of the reference to a "multi-staged LC filter" that is in the product description and partially off of the # of wires coming through the bottom panel.  I also think they're running DC heaters for the 6NS7, which is a nice upgrade over previous iterations of this amp.  I'll be bugging Pete about it more, that much is for sure.

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will probably buy for the office next year.

 

Straight ballin'!

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