Poor man's tube system?

I haven't exactly followed this thread,but I am guessing the OP might've asked about the simplest possible vacuum tube amplifier?

We call 'em spud amps. Spud. A one tuber.
(many of us suffer from profoundly atrophied senses of humor)

It is possible to build a mono amplifier using literally only one tube (i.e., one tube functionality), but such an amplifier is meant more to be cheap than hifi.
Here's an example: a stereo phonograph amplifier for inexpensive table top portables (of the early 1960s). The 60FX5 tube was specially designed to be "driven" directly by a ceramic type phono cartridge (about the same output as a "line level" component like a tuner, tape deck, or CD player). This particular design is of the AC-DC "series string" transformerless school of design. This type of circuit was also known as a "killer chassis" because there was no isolation between the AC mains and the user (except, usually, a plastic knob). It is possible to build an amp like this with an isolation transformer, rendering it safe(r).

60FX5stereoampresized by Mark Hardy, on Flickr

A more typical "spud" amp might use a single, two-section tube. Dan "Doc Bottlehead" Schmalle, in the 1990s, sold a very nice little two tube stereo amplifier, the "S*E*X" (for Single-Ended eXperimenter's) Amp. This used a two section twin triode as the voltage and power amplifier sections for each channel, and was a fine sounding little amplifier capable of about 2 watts per channel (fine for high-sensitivity loudspeakers). This amp, with two "physical" tubes (two "bottles", so to speak) has four functional vacuum tube elements (each physical tube contains two dissimilar triodes).

As it turns out, Bottlehead still offers a version of this little amp! The current morph uses two "Compactron" 6FJ7 tubes.
https://bottlehead.com/product/single-ended-experimenters-kit-3-for-headphones-sensitive-speakers/

sex3.0product600.jpg
Bottlehead has always had the best names for their products. I have the Bottlehead 'Crack' headphone amp with the 'Speedball' upgrade. :D
 
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You can not go wrong with the Bottlehead SEX amp. It is great sounding, easy and fun to build with close to moron proof assembly instructions. At the moment I am using mine powering a pair of Allison CD-6 speakers. There is a saying around Bottlehead, "music sounds better when you build it yourself".
 
To answer a few questions...
I currently have a set of Dahlquist dq8's.
Probably not the greatest speaker in the world, but they're ok for now, or should I say, a start.
I also have 2 sets of (dare i say it? Bose 301's) that I just refoamed.
1 set is sitting, the other is being run off the B setting.

I gotta wonder where some of you guys find stuff, and how you value it.
Not trying to be mean or anything, just saying what I see.
Most folks out in the open markets, such as ebay, or CL seem to do their research and most equipment is similarly priced.

I might see a set of speakers selling for say, $350, and when I research here, I find threads where guys say, oh hell, those are ok, but not worth more than $50.
Same with amps.

There are so few places that sell tube amps, and even less set up to properly demonstrate them, so everything to me seems like a crap shoot.
I want to know where you guys find these things.

Refurbed tube amps for a couple hundred? Seriously?
I have yet to see one, mind you I'm not a paid member here yet, but might just do so for the access to the barter section.

So anyways, I'm still hunting and pecking for my "sound" and as far as most of you guys are probably concerned, I'm just getting re-aquainted in the audio realm.
You might drop by my intro thread for more info.

So at this point, I'm pretty sure I'd be happy with tube stuff, but getting a foot in the door is daunting at best.
It's a bit like walking into a football field sized buffet.
 
Barter Town is a great place to buy tube amps. It is where I got a refurbished integrated amp for less than $200. BT is well worth the $25 yearly subscription. Patience also helps.
 
Just wow. Almost every headphone tube amp including the Indeed is a month wait from China.

I bought a Nobsound NS-08E heaadphone amp from Amazon, $50 delivered to my door. After reading up on what others have done with these I spent a little extra for some Amperex tubes and popped in some LM4562 Op-amps. Sounds very nice to my ears and not a lot invested. I'm itching to try it with my Emotiva power amp. If it sounds good enough they have a similar model with RCA inputs & outputs I 'd like to get.

You can get the headphone amp, some upgrade tubes and some LM4562 Op-amps from Amazon and have it in under a week.
 
I was just about to pull the trigger on a little dot mk2 on Amazon for $146.
Then all of a sudden I came across it new on ebay for $69. Kerpow! Pulled it.
First time seller. Just joined. 0 ratings.
But hey, with paypal, and ebays refund protection, how can you go wrong?

:lurk:
 
Well, I called it right.
I just got an email from ebay. Seller removed due to concerns about the account.
Oh, well, had to give it try.
KNvr6Vh.gif


If something looks too good to be true, right?

I recently came across a small 7hp engine that's popular with the minibike and gokart crowd.
New $69. (is that the new tip off price for scams?)

I actually received mine, whereas friends of mine didn't.
But it turned out to be a scam. Not sure how that one works because I actually got my product.

But being as I ordered upgrade tubes, I went ahead and ordered one from the Amazingzon.
 
Got the LDMK2 in today.
Hooked it up to my Onkyo as a preamp. Used the direct input function.
It sounds very nice!
I swear I can hear the "crunch".
 
I was just going to suggest the LDmk2. Grab a pair of the GE JAN 5654's from Riverstone Audio on Amazon. Completely different, and much better, than the sound you get out of the awful stock tubes that come with it.

Oops, I see you got different driver tubes. But still! the GE's are great.
 
I was just going to suggest the LDmk2. Grab a pair of the GE JAN 5654's from Riverstone Audio on Amazon. Completely different, and much better, than the sound you get out of the awful stock tubes that come with it.

Oops, I see you got different driver tubes. But still! the GE's are great.
If I get all addicted to rolling, I'll put those on the list too!:)
 
To answer a few questions...
I currently have a set of Dahlquist dq8's.
Probably not the greatest speaker in the world, but they're ok for now, or should I say, a start.
I also have 2 sets of (dare i say it? Bose 301's) that I just refoamed.
1 set is sitting, the other is being run off the B setting.

I gotta wonder where some of you guys find stuff, and how you value it.
Not trying to be mean or anything, just saying what I see.
Most folks out in the open markets, such as ebay, or CL seem to do their research and most equipment is similarly priced.

I might see a set of speakers selling for say, $350, and when I research here, I find threads where guys say, oh hell, those are ok, but not worth more than $50.
Same with amps.

There are so few places that sell tube amps, and even less set up to properly demonstrate them, so everything to me seems like a crap shoot.
I want to know where you guys find these things.

Refurbed tube amps for a couple hundred? Seriously?
I have yet to see one, mind you I'm not a paid member here yet, but might just do so for the access to the barter section.

So anyways, I'm still hunting and pecking for my "sound" and as far as most of you guys are probably concerned, I'm just getting re-aquainted in the audio realm.
You might drop by my intro thread for more info.

So at this point, I'm pretty sure I'd be happy with tube stuff, but getting a foot in the door is daunting at best.
It's a bit like walking into a football field sized buffet.
Your dq8s are nothing to sneeze at. I ran a pair for quite a while and liked them a lot better than the Klipsch kg4s that they replaced, which many people here love.
 
I believe I read that while using the LDmk2 as a preamp (RCA connections), the driver tubes are being used as well in the signal.
Can anyone verify this please?
 
Just popped in some Voshkod 6ZH1P-EV (6J1P-EV) = EF95 that I got yesterday.
Right off the bat, I'd say they have almost too much high end, and not much punch in the lower mids, or lows.
I'll give them some time, but for the moment, I'd say I prefer the stock ones.
Next up, I also got a pair of 5654/6AK5W CEI-Matched Pair -Blue Glass.

Don't tell anybody, but I'm kind of eyeing this amp. Yaqin MC135s

The reviews appear stellar.
 
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Hold on there bbqjoe...While that Yaqin EL34 PP amp sure looks nice, that is an expensive amp. Of course, there are stellar reviews...The reviewers want you to buy tube gear. You can find a long tunnel awaits you with tube rolling. Currently made EL34s can be quite inexpensive, compared to the original versions. However, depending on the circuit voltages and currents, newer made EL34s do not last anywhere as long as the '50s and '60s made tubes.

How did you arrive at the EL34 choice ? Do you need 35 watts per channel ? Last week, you were first trying tubes. You chose a headphone amp using pentodes and presumably are enjoying that sound nicely. That was a good start. May I suggest a bit more research on your part ? Besides being able to find second-hand bargains at lower prices, there are so many output tubes to choose from. Plus, at the $1K price point, there are even higher power tube amps at much lower prices, if you can wait for some vintage bargains...

Another consideration might be kit amps. Can you solder ? Building a kit amp can create essential electronic understanding and knowledge. Plus, the feeling of "Oh, I built that" is fantastic and cannot be understated.

Have you researched any 15 to 20 wpc tube amps ? The 6BQ5/EL84 family is very favorable, both in sound and easier cost. Unless your room is huge and your speakers way inefficient, the EL84 amps would be worthy to investigate. If you room is small and your speakers are efficient, even single ended EL84s can be sufficiently loud; and "Oh, so sweet sounding".....
 
Hold on there bbqjoe...While that Yaqin EL34 PP amp sure looks nice, that is an expensive amp. Of course, there are stellar reviews...The reviewers want you to buy tube gear. You can find a long tunnel awaits you with tube rolling. Currently made EL34s can be quite inexpensive, compared to the original versions. However, depending on the circuit voltages and currents, newer made EL34s do not last anywhere as long as the '50s and '60s made tubes.

How did you arrive at the EL34 choice ? Do you need 35 watts per channel ? Last week, you were first trying tubes. You chose a headphone amp using pentodes and presumably are enjoying that sound nicely. That was a good start. May I suggest a bit more research on your part ? Besides being able to find second-hand bargains at lower prices, there are so many output tubes to choose from. Plus, at the $1K price point, there are even higher power tube amps at much lower prices, if you can wait for some vintage bargains...

Another consideration might be kit amps. Can you solder ? Building a kit amp can create essential electronic understanding and knowledge. Plus, the feeling of "Oh, I built that" is fantastic and cannot be understated.

Have you researched any 15 to 20 wpc tube amps ? The 6BQ5/EL84 family is very favorable, both in sound and easier cost. Unless your room is huge and your speakers way inefficient, the EL84 amps would be worthy to investigate. If you room is small and your speakers are efficient, even single ended EL84s can be sufficiently loud; and "Oh, so sweet sounding".....
Thanks for your reply, very much appreciated.
I haven't pulled the trigger on anything yet. I've been spending many hours online reading and researching.
One thing I currently lack is any friends or acquaintances in the audio world, so getting any hands on listening experience to various setups is limited to only things I've heard many years ago.

I used to build mil-spec electronics where every solder joint underwent QC through a 30x microscope, so yes, I can solder, build boards, and assemble.

I've rather enthusiastically looked for some kits (somewhat like the old heathkit days) only to find limited offerings.
Some seemed rather cheap, underpowered, and not at all challenging, while others seemed a bit more intricate, and others yet getting into such high dollar levels that a person considering them, might just as well get into something already built and tested. (another downfall is my lack of nothing more than a glorified volt meter)
I am totally open to anything you can point me to!!! I would be tickled to build a decent amp.

I know from one particular experience that I do like the sound of good tube stereo amplification. It was a very elaborate setup consisting primarily of Mcintosh gear.
But, my knowledge of this tube to that tube is also limited.
I currently have a guitar amp that is tube powered having the ability to switch from and blend 6L6's and EL34's. (I like the 6l6's over the 34's, but really like the sound when blended equally.
I'm liking the little dot, and have now experimented with 3 different sets, and have returned in favor back to the stock set.
There's my tube experience in a nutshell.

You probably know my speakers at this point, and I'm a bit hesitant to try swapping much more at this point, but yet, I'm open. I recently spoke with a tech at Dahlquist, and he reported the DQ-8's were rated at 88.

As far as power goes, again, I don't need to dry my hair with a stereo set up, but occasionally as probably most people do, there are certain times when you want your own personal rock concert. :)
But if I had to choose between quality or volume, I know enough to know I'd prefer quality.

The other thing is my room.
It's pretty large. 750 sq ft, built of untreated concrete block.
Mind you it is furnished and carpeted in spots, but the walls are fairly bare, and the ceiling is pretty much acoustically dead, so some db's are required.
If I really needed shltloads of power, I could always hook up my two behringer 2400 watt PA amps. ;)

Do I really need to get into a new amp, or completely new system? Maybe not, but like everyone else, we'd all like a million dollar (sounding) system right?

Anyways, dollar for dollar, my research so far has led to the Yaqin. There's even a few folks here who seem to be quite happy with them, but as I said previously, I've not yet made any decisions, although I'd probably jump all over a mac 275 if one came my way.



I'm open, and appreciate the schooling.

Thank you.
 
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...One thing I currently lack is any friends or acquaintances in the audio world, so getting any hands on listening experience to various setups is limited to only things I've heard many years ago....
PM me if you are ever in Vegas. I can let you listen to EL84 (SE & PP), 6V6 (PP), 7868 (PP), 300B (SE) and 6BM8 (PP) tube amps.
 
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PM me if you are ever in Vegas. I can let you listen to EL84 (SE & PP), 6V6 (PP), 7868 (PP), 300B (SE) and 6BM8 (PP) tube amps.
Very cool offer.
I'm always looking for a reason/destination for a ride on the bike, so be careful what you offer. ;) I'm retired, so I got lots of extra time!
 
I've been looking hard at kits, and came across the VTA ST-170.
I'm seriously thinking about building this amp.
I also think if Santa's good to me this year, I might go ahead and build the SP14 preamp as well.
Anyone care to chime in?
 
I built and use a VTA-70. It's a great kit. The instructions are very good. You just have to carefully follow them. Depending on options they will ask to jump to instruction # etc. And support is great. As for the model 14 preamp the instructions are basic. Basically a schematic and a drawing. Roy expects you to know what your doing.
 
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