Best Tube Headphone Amp To DIY

[Parafeed]

Quote:

Originally Posted by nikongod /img/forum/go_quote.gif My amp is a CCS'd 6sn7 into 5998/6as7 cathode follower with cathode CCS.

I've been fiddling around with drivers in front of the cathode follower.... 6H30, 6SN7, C3g (triode strapped), 5965..... But I found some ECC88's that I had forgotten about, Siemens CCa's and Amperex, so that's where I'm at right now. My EL34 CF is CCS'd too.

Quote:

Originally Posted by nikongod /img/forum/go_quote.gif Do you transformer couple the output or run OTL? I have mine set up to run both ways for different headphones and single driver speakers

Both. OTL - I've been listening to 600R T1's coupled to the cathode of the EL34 using 100uF poly Obligattos. That's what I'm listening to right now. Transformer - I've had a pair of TL-404's hooked up, but I've not spent much time listening to that config. The T1's through those Obligatto caps sound very good.

 

[regal]

Interesting finding, I setup a very similiar design only as an analog stage to a DAC, Broskie calls it a Constant Current Draw Amp, I used CCS's as well. In the DAC I didn't like what the cathode follower did to the sound and ended up eliminating the cathode follower which gave much better results. I understand that cathode followers are very load dependant so that may have been the issue so I may revist this for headamp usage if you guys are liking the sound.

 

[Parafeed]

Quote:

Originally Posted by regal /img/forum/go_quote.gif Interesting finding, I setup a very similiar design only as an analog stage to a DAC, Broskie calls it a Constant Current Draw Amp, I used CCS's as well. In the DAC I didn't like what the cathode follower did to the sound and ended up eliminating the cathode follower which gave much better results. I understand that cathode followers are very load dependant so that may have been the issue so I may revist this for headamp usage if you guys are liking the sound.

It's easy to make generalizations. Cathode followers do sound "compressed" compared to the same tube without feedback. But then feedback does that. (Clue: So does damping the glass envelope of a tube when used as a triode without feedback. Try a tube as a cathode follower. Then listen to it again with a plate load. Then put a heavy tube damper on top of it or slide on a couple of silicon O rings. Notice anything? Like the damped tube sounds very similar to using it as a cathode follower. I wonder why that could be? LOL.)

Hours of fun can be had with a pair of the Hammond 119DA's, a driver, and trying various tubes as the cathode follower output. I prefer the EL34, but I've tried the EL84, 5881, 6L6, 7581, KT88, 6550 - most of what would be considered the mainstream "audio" pentodes strapped as triodes. I'm not really a fan of the regulator tubes.

Slightly off the beaten track, the A2134 is a great sounding tube when strapped as a triode and used as a cathode follower to drive phones via a step-down transformer.

 

[regal]

Quote:

Originally Posted by Parafeed /img/forum/go_quote.gif It's easy to make generalizations. Cathode followers do sound "compressed" compared to the same tube without feedback. But then feedback does that. (Clue: So does damping the glass envelope of a tube when used as a triode without feedback. Try a tube as a cathode follower. Then listen to it again with a plate load. Then put a heavy tube damper on top of it or slide on a couple of silicon O rings. Notice anything? Like the damped tube sounds very similar to using it as a cathode follower. I wonder why that could be? LOL.) Hours of fun can be had with a pair of the Hammond 119DA's, a driver, and trying various tubes as the cathode follower output. I prefer the EL34, but I've tried the EL84, 5881, 6L6, 7581, KT88, 6550 - most of what would be considered the mainstream "audio" pentodes strapped as triodes. I'm not really a fan of the regulator tubes. Slightly off the beaten track, the A2134 is a great sounding tube when strapped as a triode and used as a cathode follower to drive phones via a step-down transformer.

So would you say you prefer a good cathode follower to a classic SET plate output w/ SE gapped OPT ? I notice on your sig you are all parafeed, are these cathode follower?

 

[Parafeed]

Quote:

Originally Posted by regal /img/forum/go_quote.gif So would you say you prefer a good cathode follower to a classic SET plate output w/ SE gapped OPT ?

My general philosophy - use the right tool for the job. If you need a hammer, don't improvise with a screwdriver. But there are several different hammers to chose from.

As a general rule I like the DHT SET (without feedback) sound with speakers. Though I do use OTL's as well, with a heap of feedback. I feel that DHT SET doesn't work so well with headphones. Yes, I prefer parafeed to series feed, but that isn't a be all and end all in itself. Cathode followers can sound good, but they can sound truly terrible. The same is true for any circuit. If it sounds good, then that's what matters, not the topology.

Quote:

Originally Posted by regal /img/forum/go_quote.gif I notice on your sig you are all parafeed, are these cathode follower?

No, all the amps in my sig are plate choke loaded, parafeed. Although, the 6H30/6C45 amp uses the 6H30 as a cathode follower, direct coupled to the cathode of the 6C45. There is a paragraph about each if you look at my profile, here. The 300B amp is a partial feedback (resistor from the 300B output plate to the driver plate) design.

 

[Kitarist]

Anyone ever built anything on their own without any instructions?

 

[regal]

Quote:

Originally Posted by Kitarist /img/forum/go_quote.gif Anyone ever built anything on their own without any instructions?

Yes, best advice is to go to the tubecad website and start reading from the beginning. Once you understand how to read tube curves it'll start making sense.

 

[theHof]

I've been looking at some of the HeadWize diy projects, and I'm just wondering if there are any tube amps I could run balanced output instead of the 1/4inch output or if it'd be possible to something like this balanced. Or how would something like this perform with balanced out put instead of the 1/4 inch?

 

[nikongod]

Quote:

Originally Posted by theHof /img/forum/go_quote.gif I've been looking at some of the HeadWize diy projects, and I'm just wondering if there are any tube amps I could run balanced output instead of the 1/4inch output or if it'd be possible to something like this balanced.

Quite a few of the circuits over there have been modified to run balanced with effort ranging from simply putting 2 amps back to back (4 separate channels) to others which deliberately couple the 2 phases in various ways.

While I firmly believe there are some inherent advantages to balanced circuitry, there are also some disadvantages.

For what head-fi says: I would rather build (or buy) a balanced amp than one which sounds decent (regardless of how its made). Seriously, try to sell an amp with only 1/4" jacks. I triple dogie dare you. Clone any number of SET amps with floated OPT's that are currently in vogue but ONLY ground the secondary of the transformer and only put a 1/4" plug on it. Try to sell it for parts cost. Throw the ruiles in the face of the forum, and say what you knocked off to the ohm, mili-amp, and the volt.

Why did you bother to build that SET amp if it isnt even balanced? This oxymoron brought to you by nikongod.
Quote:

Or how would something like this perform with balanced out put instead of the 1/4 inch?

Throw caution to the wind, disregard well known safety practices, and disconnect the secondary from ground. taah-daah! its balanced. As an ironic point, that amp uses a push-pull output stage which actually is balanced regardless of what you do to the safety benefits of having the secondary of the transformer grounded.

I still haven't figured out how to get both halves of a balanced signal through 1 triode.

That amp is actually a neat circuit, and the single PCB makes for a nice first HV tube amp project although it needs a bunch of work & mods to work with headphones. At the time of posting this, the quoted text in my signature links to the thread about an older variant of that amp. Do what blackie says. at the very least try it! Searching 11ms8 will get you a thread here with lots of info on what it used to be. Dont build the 16W one, try the 8W one. The fact that the gain & cathodyne triodes are separate from the output pentodes (unlike the original version) is quite attractive to me.

 

[regal]

The whole balanced is best fad started years ago on head-fi when people were driving their 300 ohm senns with SS amps that had a gain of 2. When they went balanced they had more voltage and current so the herd accepted that balanced was required for the ultimate sound.

A properly designed tube amp doesn't need balanced outputs. Unless your amp is a few hundred feet away from your headphones be a good DIYer and not get stuck on fads, look for solid engineering.

 

[nikongod]

Quote:

Originally Posted by regal /img/forum/go_quote.gif The whole balanced is best fad started years ago on head-fi when people were driving their 300 ohm senns with SS amps that had a gain of 2. When they went balanced they had more voltage and current so the herd accepted that balanced was required for the ultimate sound.

Ignoring electrostatic amps...
futerman was doing it in the 70's on his OTL monsters.

The first (obvious) balanced headphone amp was the blockhead, which had gain of way-a-lot in an SE configuration and 6dbmore than way a lot balanced. give up.

After that came a few DIY amps. I would hope that a DIYer has the knowledge and self discipline to select a good gain for himself.

Then came the singlepower balanced OTL amps. what fun. 2 common cathode 6sn7 (or better!) as the gain stage. I see gain in the 20-30 range how about you?

The RSA B52 rolled up on the scene: I dont know what the voltage gain is on his gear. My guess is 7 SE/14balanced based on the schematics I have seen & an educated guess.

*note: the gain of the B52/SP amps may sag somewhat in response to low impedance loads. numbers are into a high impedance load.
Quote:

A properly designed tube amp doesn't need balanced outputs.

could you elaborate on that?

Yet again you start up with "properly designed", What does that mean? Some people quite enjoy OTL amps, can you support this statement in the face of that?

Others like push-pull transformer coupled amps. Again, can you back it up?

A whole lot of nothing, but thanks for posting drivel.
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Unless your amp is a few hundred feet away from your headphones be a good DIYer and not get stuck on fads, look for solid engineering.

Its a shame you are this closed minded, and have taken this as your argument for "the only reason" to go balanced. Bummer.

 

[Beefy]

Am I the only one who is thoroughly fed up with regal and Parafeed's frequent bickering? Take it to PM guys

 

[nikongod]

Quote:

Originally Posted by Beefy /img/forum/go_quote.gif Am I the only one who is thoroughly fed up with regal and Parafeed's frequent bickering? Take it to PM guys

I dont think you are alone.

OTOH, most of it is regal spouting rubbish and Parafeed calling him on it. Check it out, its quite consistent. Really the only reason its coming down to Parafeed is he is very good at calling it and dosnt seem afraid to at all.. There is plenty of fail in plenty of regal's posts.

From what I have read from Parafeed he seems like a nice guy when he isnt pointing out the fail in regal's posts, and is clearly a knowledgeable designer regardless. Id happily take his advice on a tricky q and probably be better for it.

 

[Parafeed]

Quote:

Originally Posted by Beefy /img/forum/go_quote.gif Am I the only one who is thoroughly fed up with regal and Parafeed's frequent bickering? Take it to PM guys

I wouldn't call it bickering, but I'm sorry if my occasional taking issue with regal in public is irritating. Generally I bite my tongue. Sometimes it is hard to do so when bad advice is given or a slight is aimed at a commercial design or designer, especially when regal makes some sort of "negative" comment, (usually totally unjustified or tenuous to say the least), that might cost the manufacturer concerned a sale. It's not personal.

 

[regal]

Look in this thread Parafeed and I weren't bickering, we were sharing our experiences with different designs. NikonGod on the other hand jumps in with personal attacks and tries to prove how smart he is. I've contributed to the DIY community many times, my goal here isn't to the same as yours. I like to see people learn, learn from others and their mistakes/successes, and go to great lengths to avoid seeing a guy running up his credit card on a commercial amp he can't afford. DIY is about sharing schematics/designs, having fun building an amp that competes with anything on the market, not trying to prove how clever you are.