All interesting thoughts. At this point I don’t have an 800 series Senn, but I may look around a bit at what’s available used to compare. Lou makes a good point about resale
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I have the Valhalla 2 and it pairs well with dynamic drivers, especially the HD6XX. It’s also nice with the Focal Elex on low gain.
I haven’t heard the Bottlehead Crack, only more expensive options like the Mainline. If you are looking for a really warm sound signature, Valhalla is one of the more neutral OTL tube amps. But it’s very good for the price, tho it is worth upgrading the tubes.
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Depends on what you mean by “full tube.” Valhalla does not employ tubes for rectification of the AC in the power supply. The WA-2 does. Other reasons for the price being so much lower:
- The WA-2 is point-to-point wired. The Valhalla uses a PCB.
- The WA-2 has a much fancier, “pseudo dual” power supply.
- The WA-2 has a much fancier chassis, with separate covers on the transformers and chokes.
- The WA-2 has four inputs while Valhalla has only one.
It all adds up. We’re talking a $1500 amp vs a $300 amp. Percentage-wise, that’s like comparing cars costing $30k and $150k. The Schiit may indeed be too cheap to scratch the itch, but there’s a (fairly) easy way to find out.
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Cost is all in the power supply for cheap tube amps, and that’s especially true for OTL amps, it’s about clever design choices as much as anything to keep cost down. Running at lower voltages can help a lot with cost.
I haven’t heard the Valhalla so I can’t comment on it.
The electrolytics look to be in the Power supply and probably coupling the output.
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Thank you please link specific models, best from Amazon under $100
Following my testing of a cheap OTL amp (Darkvoice 336), and living with the less cheap but still fundamentally cheap Bottlehead Crack OTL, I’d pass at this point. That’s because the forbidden qualities of high-end transformers and capacitors make the roughness and flaws of products in this price class obvious.
OTL amps don’t have transformers. That’s literally what OTL means.
I thought the Crack sounded amazing TBH, though I did eventually upgrade to a (transformer-having) ZMF Pendant, but that’s in a different price category. (I’ve never heard the Valhalla, but I know people who like it a lot.)
OTL means Output Transformer-Less OTL.
They still do have power transformers. Many vendors make a big deal about using proprietary or toroidal transformers in their OTL amps.
See Bottlehead. See Decware’s UFO (CSP3 OTL amp). Much of the cost of an amp lies in its transformers, but AFAIK every amp has a power transformer of some sort, or it couldn’t amplify.
Compare the single transformers above (OTL) to the triple transformers of the Amps&Sound Kenzie.
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I stand corrected.
20 characters.
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The issue with tube amps and power is mostly to do with the high voltages, it means all your passive components get more expensive, a 200V rail means all the caps in the PSU have to be rated to at least 300V.
They also have to provide AT LEAST 2 separate voltages this can be done with a single transformer, one for the heater, and one for the High Voltage line. But for example my DHT tube amps PSU contains no less than 4 transformers (one of which is providing 2 voltages) + associated chokes, because the DHT tubes can’t share heater power.
FWIW High powered class A SS amps have a somewhat different issue that makes their power supplies expensive, they draw such high currents they need massive amounts of capacitance to smooth the rail enough to either use unregulated or regulate. It’s still usually less expensive than the power supply in a tube amp.
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Every amp has a power supply of some sort. Some amps, mostly class D and inexpensive hybrids, use a switch mode power supply (SMPS) instead of a transformer-based linear power supply.
Technically, it’s possible to make an SMPS that can handle the voltages tubes require, but it would use expensive, difficult-to-source parts (power transistors and Zener diodes), plus the associated caps would be just as expensive as in a linear supply. I don’t think any real manufacturer would do it. Maybe some crazy DIY-er somewhere…
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True story, at that price it’s possible to just give it a whirl! And I can’t believe my brain ignored tube rectification there… for shame! 
One of the ways the Hagerman Tuba saves on cost is to use a relatively simple Boost Converter circuit to generate the 150V B+ it uses from a 15V DC supply.
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Good point. There may be some relatively inexpensive ways to get an SMPS to work.
But the Hagerman still involves a pair of substantial chokes. I wonder if it’s really saving all that much vs a transformer.
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I think it’s a choke and an output transformer/channel.
The Choke looks to be the anode load, and he’s capacitively coupling to the output transformer (parafeed) which means he can use a cheaper none air gapped transformer, because it doesn’t have to handle the DC offset between input and output. So the cost trade off is choke + cheaper output transformer vs normal tube output transformer, he’s almost certainly saving cost with the combination.
It’s an interesting compromise, and one that sounds quite good.
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Well, you’re making me consider them. The Feliks in particular seems like a good deal, although I’ve seen a used Woo WA2 1st generation in that same price range. I just don’t know that I need any of these. Looking around, not even sure where I would put them in my limited space.
It’s just difficult these days to hear what this stuff sounds like. I’m old-fashioned enough that I don’t like to rely on sending things back to a company if I change my mind. Seems sort of unfair.
But still, @Lou_Ford’s point about trying and reselling does make sense. It’s just a matter of scale. I know I p*** um, er fritter away $299 on non-audio crap without much thought.
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I’ve got to say it’s worth giving it a whirl, especially if you have some dynamic headphones that appreciate it.
I just hooked up my Focal Elex after a session with the same headphones on the Jotunheim 2.
It works so beautifully with the Elex and Brimar Triple Mica 1956 (with adapters) & Foton 6N6P Gold Grid tubes. The Elex sound good with the Jot 2, they sound lovely with the Valhalla.
I wouldn’t describe it as a warm amp, but the soundstage is holographic and it is what I can only describe as euphonic. I feel the music rather than listen to it. Maybe warmish, but with good treble clarity.
The tubes I have were recommended to me by someone as the best value and most piece appropriate tubes for the amp. Can’t say I disagree, but it is also nice with the stock tubes. But you do have the opportunity to take the journey and experiment.
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LTA microZOTL MZ2 Headphone Amp / Preamp / 1-watt Speaker Amp by Linear Tube Audio
I think this qualifies even though they also offer a linear power supply with a transformer for an extra 500 beans.
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Side note about the LTA sound: I demoed LTA’s amps from entry level to $7K+ at Capital AudioFest a couple years ago. I didn’t like that they paired their cheap amp with a cheap DAC and cheap headphones, while they paired their expensive amp with an expensive DAC and expensive headphones. Were they hiding that all three tiers sound the same? That there’s a minimal difference between them? Hmmm?
Anyhow, based on their TOTL setup, I took the LTA as very close to a nice solid state amp. It’s not a bad sound, but pretty neutral (aka linear) with sharp definition and not much like a mainstream easier-on-the-ears tube amp. From what I’ve read about the Valhalla, perhaps LTA reflects upgraded versions of a similar sound profile. As above I’d pass on the Valhalla because I think I’ve outgrown that tier. I’d pass on every LTA for being too similar to a solid state.
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Home set up: chord tt2 plus Mscaler, AK sp2000
I currently have ZMF verite open.
I like to listen to: variety Pink floyd/bob D/foo fighters/Joni Mitcjell.
Wondering If I was to buy one other pair of headphones for the above set up. what should it be?
Interested in advice.
Best and Thanks
M
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FWIW, I tend to trust your comments and your ear. I wasn’t really looking at the LTA, I just noticed it when @Lou_Ford’s comment had me sensitized to the power supply consideration. Given what I already own, I suspect you are correct about the Valhalla, and that my Lyr3 gives me at least as much of that tubey sound (e.g. not too much at all). I’ve generally been running the Lyr3 with the LSSST anyway.
It appears as if the Feliks Echo Mark II is one of the few amps in my range and the Woo WA2 - if I find something used - might be another. $300 isn’t any issue, but I get my bowels in an uproar at the $1000 mark for something that’s a toy I don’t really need. I see a CERN LAMP from somewhere - Poland? but don’t know a thing about it.
Is there anything else that you or anyone can point out? I tend to check Audiogon for used first, the US Audio Mart, then some of the other fora that have buy/sell listings last.
This is more a mild itch rather than something I really need to scratch.
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