a few points to consider (in no particular order) given the posts so far:
* using an input tranny, .. make sure your preamp can drive it
* re. the 807, .. 6bg6 should work in an octal socket, and maybe be cheaper .though it still has the funky top cap. i've had a 6bg6 pp project in the pipeline for the past year or so, but its one of those cursed projects that never gets off the ground (hint, ... UN)
* re. 300B, .. IMHO, i think the sound is nice but overhyped. YMMV
i think your best low power bet will be a push pull 2a3, ... use an interstage tranny if you want to make things real simple.
else, 6v6 amps rock, can't beat that tone
* using an input tranny, .. make sure your preamp can drive it
* re. the 807, .. 6bg6 should work in an octal socket, and maybe be cheaper .though it still has the funky top cap. i've had a 6bg6 pp project in the pipeline for the past year or so, but its one of those cursed projects that never gets off the ground (hint, ... UN)
* re. 300B, .. IMHO, i think the sound is nice but overhyped. YMMV
i think your best low power bet will be a push pull 2a3, ... use an interstage tranny if you want to make things real simple.
else, 6v6 amps rock, can't beat that tone
Some people have gone the PP lane and never return to the SE path. But do not simply replicate old pp designs I would suggest. You do not fly those old choppers 
so why not use state of the art PP:
http://home.pacifier.com/~gpimm/1624.gif
http://www.vacuumstate.com/schematics/pp-1c_s.gif
so why not use state of the art PP:http://home.pacifier.com/~gpimm/1624.gif
http://www.vacuumstate.com/schematics/pp-1c_s.gif
If I were mr Annan I would:
1) allow people ride my helicopter
2) build a PP 2A3, as you like these bottles, working in class A1 (6-7W into 5K) possibly IT coupled and hopefully with a splitter transfomer at the input.
If I were me I would:
1) buy the biggest helicopter
2) upgrade my class A1-transformers all the way-2A3 PP using a splitter autoformer by MQ.
I am very happy with it.
Ciao.
Gianluca
1) allow people ride my helicopter
2) build a PP 2A3, as you like these bottles, working in class A1 (6-7W into 5K) possibly IT coupled and hopefully with a splitter transfomer at the input.
If I were me I would:
1) buy the biggest helicopter
2) upgrade my class A1-transformers all the way-2A3 PP using a splitter autoformer by MQ.
I am very happy with it.
Ciao.
Gianluca
Konnichiwa,
Well, my first advise is to stick to SE, unless you must have loads of power. I make quite excellent sounding PP Amp's but I keep comming back to SE. I equally keep coming back to the 300B, well implemented it does not add much coloration, it has just the right sort of power to manage medium efficient (eg 95 - 100db/W/m) speakers, for 45, 10Y etc you really need huge high efficient (105db/W/m +) speakers and they get well big.
If however you are absolutely bent on trying PP, all the best sounding PP Amplifiers I know use the EL84. I would build such an amp strictly as excercise in frugality, this means using the classic sansui 500 style circuit with an ECC83 (or better 12DW7 - the ECC82 halve as phasesplitter, the ECC83 halve as input Amp), probably the output stage in ultralinear or triode. You'll get no more power than a 300B SE can do that way, but cost is a fraction.
As an aside, the EXTREME frugalphile PP Tube Amp uses a 6AS7 and due to the very low anode impedance you can get away using a dirt cheap mains torroidal transformer as output transformer and two more at higher power for mains. It even looks like an SE Amp.... ;-)
Google and Search DIY Audio for Maurits if you want more details (you find some comments of mine there).
If you live with even less power, the 6AS7 can be used as SRPP with around 550V +B and a 100V Line Speaker transformer as parallel feed output that way it is pretty much a SE Amp.
Sayonara
Kofi Annan said:
Well, my first advise is to stick to SE, unless you must have loads of power. I make quite excellent sounding PP Amp's but I keep comming back to SE. I equally keep coming back to the 300B, well implemented it does not add much coloration, it has just the right sort of power to manage medium efficient (eg 95 - 100db/W/m) speakers, for 45, 10Y etc you really need huge high efficient (105db/W/m +) speakers and they get well big.
If however you are absolutely bent on trying PP, all the best sounding PP Amplifiers I know use the EL84. I would build such an amp strictly as excercise in frugality, this means using the classic sansui 500 style circuit with an ECC83 (or better 12DW7 - the ECC82 halve as phasesplitter, the ECC83 halve as input Amp), probably the output stage in ultralinear or triode. You'll get no more power than a 300B SE can do that way, but cost is a fraction.
As an aside, the EXTREME frugalphile PP Tube Amp uses a 6AS7 and due to the very low anode impedance you can get away using a dirt cheap mains torroidal transformer as output transformer and two more at higher power for mains. It even looks like an SE Amp.... ;-)
Google and Search DIY Audio for Maurits if you want more details (you find some comments of mine there).
If you live with even less power, the 6AS7 can be used as SRPP with around 550V +B and a 100V Line Speaker transformer as parallel feed output that way it is pretty much a SE Amp.
Sayonara
Heya Kofi,
I'm pretty new here so assign what value you will to my opinion
I think in some ways I've come at DIY tube amps from a different direction than a large portion of builders and went PP from the start.
I started out restoring old Scott units and thought the sound was really special.
For a purely subjective opinion, I think PP sounds like really good solid state with a good dose of the "tube sound" we all like thrown in. Think clarity, detail and good base of SS with the ability to reproduce the human voice, soundstage and dimensionality of tubes-and most of all for me, no listening fatigue even at high volume for extended periods.
As far as distortion-whether you build SET or PP, with distortion levels below 1% chances are unless you're a bat you won't hear it.
I think if you're gonna go PP then go all the way. 20-40wpc, using either a pentode/triode or dual triode for gain and phase splitting, resistor coupling for best frequency response. Accept that a PP amp will be more complicated, more resistors, more caps etc. Embrace it and be proud of the complicated beast you've built.
Remember a PP amp will operate at almost class A at low levels which is where most of us listen anyway.
Depending on your comfort and experience level I'd be willing to share the circuit I've been building. Stereo single chassis, PP 7591s, dual 5AR4s, dual 0A3s for screen regulation and 6AN8s in a cathodyne arrangement for gain/phase splitting. Separate bias control for each channel, separate DC and AC balance for each channel as well. 35-40 wpc, less than .3% distortion at a full 35 watts from 20-20khz. Less than 1% ripple. At 20 watts absolutely flat from 20-20k and @ .1% distortion.
Circuit was drawn by the tube engineering department at Westinghouse. I love the 7591 tube and I figure if anyone could come up with a great circuit using this tube it would be the engineers who helped design the tube itself.
Is it complicated? Relatively. But if a monkey like me can build it anybody can. It is a vintage PP circuit in all its glory-and since there hasn't been any earth-shattering improvements in PP tube circuits for a long time-there's no shame in building it.
Just my $.02. Probably worth less.
Best,
mr mojo
I'm pretty new here so assign what value you will to my opinion
I think in some ways I've come at DIY tube amps from a different direction than a large portion of builders and went PP from the start.
I started out restoring old Scott units and thought the sound was really special.
For a purely subjective opinion, I think PP sounds like really good solid state with a good dose of the "tube sound" we all like thrown in. Think clarity, detail and good base of SS with the ability to reproduce the human voice, soundstage and dimensionality of tubes-and most of all for me, no listening fatigue even at high volume for extended periods.
As far as distortion-whether you build SET or PP, with distortion levels below 1% chances are unless you're a bat you won't hear it.
I think if you're gonna go PP then go all the way. 20-40wpc, using either a pentode/triode or dual triode for gain and phase splitting, resistor coupling for best frequency response. Accept that a PP amp will be more complicated, more resistors, more caps etc. Embrace it and be proud of the complicated beast you've built.
Remember a PP amp will operate at almost class A at low levels which is where most of us listen anyway.
Depending on your comfort and experience level I'd be willing to share the circuit I've been building. Stereo single chassis, PP 7591s, dual 5AR4s, dual 0A3s for screen regulation and 6AN8s in a cathodyne arrangement for gain/phase splitting. Separate bias control for each channel, separate DC and AC balance for each channel as well. 35-40 wpc, less than .3% distortion at a full 35 watts from 20-20khz. Less than 1% ripple. At 20 watts absolutely flat from 20-20k and @ .1% distortion.
Circuit was drawn by the tube engineering department at Westinghouse. I love the 7591 tube and I figure if anyone could come up with a great circuit using this tube it would be the engineers who helped design the tube itself.
Is it complicated? Relatively. But if a monkey like me can build it anybody can. It is a vintage PP circuit in all its glory-and since there hasn't been any earth-shattering improvements in PP tube circuits for a long time-there's no shame in building it.
Just my $.02. Probably worth less.
Best,
mr mojo
http://www.meta-gizmo.com/Tri/sunschematic.html
http://www.meta-gizmo.com/Tri/interstage.html
Kofi, here you go. The top one uses 300bees but throw some Sovtek 2A3's in there with the fixs (filament etc)
The bottom one uses 6B4G's which is the 6v version of the 2A3.
I built the pp300Beeee version and then changed to 2A3s.
They use transformers for phase splitting.
Not my cup of tea but .......
Andrew
http://www.meta-gizmo.com/Tri/interstage.html
Kofi, here you go. The top one uses 300bees but throw some Sovtek 2A3's in there with the fixs (filament etc)
The bottom one uses 6B4G's which is the 6v version of the 2A3.
I built the pp300Beeee version and then changed to 2A3s.
They use transformers for phase splitting.
Not my cup of tea but .......
Andrew
Kofi,
Problem solved
http://euphoniaaudio.netfirms.com/ea/nfoscomm/catalog/product_info.php?cPath=47&products_id=101
This driver board will drive your PP pentode / tetrode or triodes 2A3 /6B4G.
It uses a Sowter tranny up front for splitting duties.
more here http://www.pmillett.com/push-pull_kt88_class_a_amp_with_universal_driver_pcb.htm
So, wire up a pair of these boards and then set up the output stage to be individually swappable / mountable (new words) and make octal and 4 pin output boards so you can swap to your hearts content.
The driver stage remains the same so you can make a convertible output stage amp and when you make the output boards all the same size you simply swap the output stage only, same mounting and add some barrier strips or plugs for your connections and voila!
Thats going to cost you some more heli rides since I don't get to fly them anymore
Problem solved
http://euphoniaaudio.netfirms.com/ea/nfoscomm/catalog/product_info.php?cPath=47&products_id=101
This driver board will drive your PP pentode / tetrode or triodes 2A3 /6B4G.
It uses a Sowter tranny up front for splitting duties.
more here http://www.pmillett.com/push-pull_kt88_class_a_amp_with_universal_driver_pcb.htm
So, wire up a pair of these boards and then set up the output stage to be individually swappable / mountable (new words) and make octal and 4 pin output boards so you can swap to your hearts content.
The driver stage remains the same so you can make a convertible output stage amp and when you make the output boards all the same size you simply swap the output stage only, same mounting and add some barrier strips or plugs for your connections and voila!
Thats going to cost you some more heli rides since I don't get to fly them anymore
frank de grove posted a complete PP 2A3 in this forum... it goes to around 7 wpc
angela instruments also has a PP 2A3 with 6SN7 driver/splitter.
thorsten's comment on the EL84 supports most of my friends who's into vintage gear that the EL84 is hard to beat (subjectively) in sonics. i was thinking of making a Dynaco ST-35 clone myself.
angela instruments also has a PP 2A3 with 6SN7 driver/splitter.
thorsten's comment on the EL84 supports most of my friends who's into vintage gear that the EL84 is hard to beat (subjectively) in sonics. i was thinking of making a Dynaco ST-35 clone myself.
Whew! Tried to reply earlier, but I've had a helluva day. So, I burned out a resistor de-soldering it and I was waiting for some new wirewounds to arrive so I could finish the Thorsten Phono Pre which, if you've been following my soap opera, has been a long time coming.
I finally got them today and was all set to start soldering when I couldn't find the remaining components for the PSU. I did, however, find a bag not dissimilar to the bag in which I have been keeping the other components. This bag did not contain any components, however; but it did contain a pocket pizza, chips, diet cola and a granola bar.
Being the detective that I am, I arrived at the conclusion that Mrs. Annan's afternoon meal likely consisted of five 47uF, 450V electrolytics, four 1.2K 12W wirewound resistors (one damaged), eight ultrafast rectifier diodes in the TO-220 package and some tinned copper 22AWG wire.
I the meantime, I was left trying to solder a pocket pizza and a granola bar together in parallel for PSU smoothing. *******' mess.
Nice girl, really.
Anyway, I am really, really grateful for all the responses.
Jeez, I knew this would be the case. I really like the SET sound, but let's see what else was added to the response queue while Mrs. Annan was choking down wirewonds with a side of Fairchilds.
Sounds reasonable, but ixnay on the opperschay.
OK-- I like this description. This is what I need to know. Thanks.
Errr... Aahhh... I like dogs!
If my comfort and experience are the contingency, its probably best you don't expose your this design to my ignorance. I can handle some intermediate stuff, but I'm a-scared of what you described. Maybe its easier than it sounds?
If you say, "very interesting" in your best Artie Johnson voice, you'll get my general reaction to this. This looks good and will be a real consideration, should I stay with the push-pull concept.
OK. This is good news. I'll check these out.
Here's my overall feeling, though: I think I may be too enticed by an SET 300b design to actually go with a push-pull for the following reasons:
- More than one poster has mentioned that they keep going back to SET designs.
- SETs would mate will with my Fostexseseses (206Es in the 208EZ backhorn)
- 300bs are cool
- More power, same SET sound
- 300bs are cool
- Hail yeah
So, do I have a dynamic personality or am I fickle?
See? You thought this would be easy, but I made it hard. Story of my life.
So, since I enjoy the SET sound, can anyone trump the 300b SET with a good push-pull? If not, can anyone recommend a relatively inexpensive 300b SET design that sounds nice? Any experience with the Angela Instruments 300b design?
Do you feel ripped off yet? You will. I have that effect on people.
Sorry for all the confusion, as always.
Yours in indecision,
Kofi
I finally got them today and was all set to start soldering when I couldn't find the remaining components for the PSU. I did, however, find a bag not dissimilar to the bag in which I have been keeping the other components. This bag did not contain any components, however; but it did contain a pocket pizza, chips, diet cola and a granola bar.
Being the detective that I am, I arrived at the conclusion that Mrs. Annan's afternoon meal likely consisted of five 47uF, 450V electrolytics, four 1.2K 12W wirewound resistors (one damaged), eight ultrafast rectifier diodes in the TO-220 package and some tinned copper 22AWG wire.
I the meantime, I was left trying to solder a pocket pizza and a granola bar together in parallel for PSU smoothing. *******' mess.
Nice girl, really.
Anyway, I am really, really grateful for all the responses.
Jeez, I knew this would be the case. I really like the SET sound, but let's see what else was added to the response queue while Mrs. Annan was choking down wirewonds with a side of Fairchilds.
Sounds reasonable, but ixnay on the opperschay.
OK-- I like this description. This is what I need to know. Thanks.
Errr... Aahhh... I like dogs!
If my comfort and experience are the contingency, its probably best you don't expose your this design to my ignorance. I can handle some intermediate stuff, but I'm a-scared of what you described. Maybe its easier than it sounds?
If you say, "very interesting" in your best Artie Johnson voice, you'll get my general reaction to this. This looks good and will be a real consideration, should I stay with the push-pull concept.
OK. This is good news. I'll check these out.
Here's my overall feeling, though: I think I may be too enticed by an SET 300b design to actually go with a push-pull for the following reasons:
- More than one poster has mentioned that they keep going back to SET designs.
- SETs would mate will with my Fostexseseses (206Es in the 208EZ backhorn)
- 300bs are cool
- More power, same SET sound
- 300bs are cool
- Hail yeah
So, do I have a dynamic personality or am I fickle?
See? You thought this would be easy, but I made it hard. Story of my life.
So, since I enjoy the SET sound, can anyone trump the 300b SET with a good push-pull? If not, can anyone recommend a relatively inexpensive 300b SET design that sounds nice? Any experience with the Angela Instruments 300b design?
Do you feel ripped off yet? You will. I have that effect on people.
Sorry for all the confusion, as always.
Yours in indecision,
Kofi
Just for the record... I wouldn't even consider a single ended design. Just so's you know that affection for those Model Ts is not universal. Too little power, too much coloration for my tastes. Granted, lots of people love that coloration, but I'd rather be able to turn effects on and off at will.
Try both and see what you prefer. A p-p EL84 amp will be cheap, easy, and probably pretty good. To put it in perspective, the cost of my entire EL84 p-p amp was less than a single 300B tube.
Try both and see what you prefer. A p-p EL84 amp will be cheap, easy, and probably pretty good. To put it in perspective, the cost of my entire EL84 p-p amp was less than a single 300B tube.
Kofi,
If you mean this amp
I babysat this amp for about two weeks and found that it sounds too sweet and too slow for my liking.
I believe Thorsten has the most experience in tweaking this design, as has made various posts about this in the Asylum IIRC.
@sy, you must be referring about those WE300Bs? but a TJ mesh can be had for just a little over $100 per pair.
If you mean this amp
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I babysat this amp for about two weeks and found that it sounds too sweet and too slow for my liking.
I believe Thorsten has the most experience in tweaking this design, as has made various posts about this in the Asylum IIRC.
@sy, you must be referring about those WE300Bs? but a TJ mesh can be had for just a little over $100 per pair.
Good information. The EL-84 does sound intriguing, but I'm thinking that the sound may be more clinical than the SET. Maybe what I'm noticing is the coloration of the SET?
Hmmmm... has anyone had any experience with that amp with Thorsten's tweaks installed?
Man. I'm seriously conflicted here. Push-pull or SET? Unified Iraq or Kurdish, Sunni and Shiite sections?
Grrrr....
Kofi
Kofi Annan said:
Thinking is a wonderful thing. Building and listening is even better.
For my tastes, most SEs have a distinctive coloration, a sort of honeyed brightness that makes music sound much more "real" than real. Sort of the MSG of audio. And they change the sound quite dramatically, not surprising given that with real speakers, the frequency response will be anything but flat. Expensive tone controls which cannot be easily adjusted. If that EQ happens to suit your speakers and your tastes, and you like the honey glaze, you'll become a raving SE fan. For me, it doesn't, I don't, so they are banished from my listening rooms.
Konnichiwa,
I hear this argument about "tone controls" again and again. And guess what, it is about as valid as it was when it was first advanced, namly absolutely invalid.
On average the worst deviations you get with a competently implemented feedbackless SE Amplifier are in the region of +/-2db and these in the LF region where the speaker has great impedance swings due to the fundamental driver resonance. Given that this invariably happens in the modal region of the room any frequency response linearity is long history anyway.
So, SET's MAY change the sound dramatically in subjective terms, but in objective terms they change the frequency response less than moving your head a few inch or your speakers.
This is easily ascertained by anyone given the simple expedient of inserting a 2.2 Ohm to 2.7 Ohm resistor in series with their speakers. This is the output impedance of an SE Amplifier that is well implemented. Try it (not just YOU SY) and see how much the sound really changes, also compare this to the sonic difference a real SE Amplifier produces and you find a huge gap between the two.
I will still propose the simple hyphotesis that Zero Feedback SE Amplifiers do not ONLY sound the way they do because of their production of certain types of distortion (otherwise it would be trivial to produce a cheap SS Amplifier that replicates this behaviour and it is not, I tried - though I admit that a certain amount of "Aphex" is present at very high levels), but because of the absence of certain types of distortion not covered by traditional amplifier specifications.
Of course, a typhical SE Amplifier based system tends to also use speakers that are substantiatively freer from certain types of distortion commonly charaterised in Amplifiers, but omited in speakers, so the combination may very well be one that overall provides a drastically different sonic result.
If it is subjectively closer to reality or not can only be ascertained when testing a recording of a known event in known acoustics (and with a knowledge of the fundamental differences between event and recording) on the system. I found that with a well implemented SE Amplifier based system the gap is reduced. It does not make the recording more real than the actual original event, but it does seem to provide a closer subjective match.
Sayonara
SY said:
I hear this argument about "tone controls" again and again. And guess what, it is about as valid as it was when it was first advanced, namly absolutely invalid.
On average the worst deviations you get with a competently implemented feedbackless SE Amplifier are in the region of +/-2db and these in the LF region where the speaker has great impedance swings due to the fundamental driver resonance. Given that this invariably happens in the modal region of the room any frequency response linearity is long history anyway.
So, SET's MAY change the sound dramatically in subjective terms, but in objective terms they change the frequency response less than moving your head a few inch or your speakers.
This is easily ascertained by anyone given the simple expedient of inserting a 2.2 Ohm to 2.7 Ohm resistor in series with their speakers. This is the output impedance of an SE Amplifier that is well implemented. Try it (not just YOU SY) and see how much the sound really changes, also compare this to the sonic difference a real SE Amplifier produces and you find a huge gap between the two.
I will still propose the simple hyphotesis that Zero Feedback SE Amplifiers do not ONLY sound the way they do because of their production of certain types of distortion (otherwise it would be trivial to produce a cheap SS Amplifier that replicates this behaviour and it is not, I tried - though I admit that a certain amount of "Aphex" is present at very high levels), but because of the absence of certain types of distortion not covered by traditional amplifier specifications.
Of course, a typhical SE Amplifier based system tends to also use speakers that are substantiatively freer from certain types of distortion commonly charaterised in Amplifiers, but omited in speakers, so the combination may very well be one that overall provides a drastically different sonic result.
If it is subjectively closer to reality or not can only be ascertained when testing a recording of a known event in known acoustics (and with a knowledge of the fundamental differences between event and recording) on the system. I found that with a well implemented SE Amplifier based system the gap is reduced. It does not make the recording more real than the actual original event, but it does seem to provide a closer subjective match.
Sayonara
Konnichiwa,
Define your aims. Do you want to:
1) Try cheaply "Push-Pull" sound to see if you like it (proceed to EL84PP)
2) Get an "Edge of the Art" high power PP Amplifier to drive these horrible powersinks masquerading as "High End Loudspeaker" (proceed to multiple parallel push-pull KT88, don't cheap out, 4pair Monoblocks are the job)
3) Get the best possible sound within a limited budget for your fairly sensitive speakers (proceed to 300B SE and build the Amp with a certain amount of universality in mind, methinks the DRD/Monkey with a D3a driver is probably best for that)
4) Something else I have not thought off
Sayonara
Kofi Annan said:
Define your aims. Do you want to:
1) Try cheaply "Push-Pull" sound to see if you like it (proceed to EL84PP)
2) Get an "Edge of the Art" high power PP Amplifier to drive these horrible powersinks masquerading as "High End Loudspeaker" (proceed to multiple parallel push-pull KT88, don't cheap out, 4pair Monoblocks are the job)
3) Get the best possible sound within a limited budget for your fairly sensitive speakers (proceed to 300B SE and build the Amp with a certain amount of universality in mind, methinks the DRD/Monkey with a D3a driver is probably best for that)
4) Something else I have not thought off
Sayonara
Kofi,
Please believe me-when I say if a monkey like me can build it anyone can.
Really.
I'm a graphic artist by trade and training. Anything more than algebra sends the tachometer in my brain into the red. I've no illusions and no asperations of being anything more than someone who draws pictures for a living but I still enjoy the challenge of restoring and building tube equipment.
My reading has led me to think that the difference between SET and PP are in some ways relatively minor. If either a triode or a pentode is used within the most linear portion of its' characteristic curve they will sound similar. The pleasing distortion of SET will only come into play when the triode is over-driven.
In fact, some friends and I (the friends being quite a bit smarter than I) set up a blind test in which DIY SETs, vintage and DIY PP as well as some EXPENSIVE SS gear were all set up to use the same speakers, source and cables, volume levels of each were matched and while behind a screen one person used a rotary switch to switch between each.
Guess what. We thought they all sounded great and not one of us could consistantly distiguish which was which. We heard some differences-but it depended almost entirely on the source and we found ourselves just as likely to choose the SETs, PP or SS at any given time.
Maybe none in our group possesses the "golden ears" of some audiophiles, but we all recognize and search for great sound to the extent of building or restoring our own tube gear so that has to carry at least a little weight.
My point is, good sound is good sound. It can just as easily come from SET, PP or SS. It sure does look a lot prettier when it comes from tubes, which the artistic side of me enjoys deeply.
I chose PP because I enjoy the beauty of tubes and my experiences with PP amps has led me to the 7591 as the best sounding tube for my ears. I've lived with KT66s, 6L6GCs, 7591s and EL34s, all in fully restored and correctly operating amps and I found the 7591s to have the detail, clarity and bass of the 6L6 family but with the full mid-range of the EL34s.
I think in the end the question really comes down to power, complexity and cost.
A SET is in some ways simpler to build, but on the backside the advantage of simplicity is offset by the cost of building or buying speakers to suit.
A PP is in some ways the exact opposite. The advantage of using less efficent speakers is offset by the more complicated building of a PP amp.
Either one can give great results. The question is which solution works best for you?
Best,
mr mojo
Please believe me-when I say if a monkey like me can build it anyone can.
Really.
I'm a graphic artist by trade and training. Anything more than algebra sends the tachometer in my brain into the red. I've no illusions and no asperations of being anything more than someone who draws pictures for a living but I still enjoy the challenge of restoring and building tube equipment.
My reading has led me to think that the difference between SET and PP are in some ways relatively minor. If either a triode or a pentode is used within the most linear portion of its' characteristic curve they will sound similar. The pleasing distortion of SET will only come into play when the triode is over-driven.
In fact, some friends and I (the friends being quite a bit smarter than I) set up a blind test in which DIY SETs, vintage and DIY PP as well as some EXPENSIVE SS gear were all set up to use the same speakers, source and cables, volume levels of each were matched and while behind a screen one person used a rotary switch to switch between each.
Guess what. We thought they all sounded great and not one of us could consistantly distiguish which was which. We heard some differences-but it depended almost entirely on the source and we found ourselves just as likely to choose the SETs, PP or SS at any given time.
Maybe none in our group possesses the "golden ears" of some audiophiles, but we all recognize and search for great sound to the extent of building or restoring our own tube gear so that has to carry at least a little weight.
My point is, good sound is good sound. It can just as easily come from SET, PP or SS. It sure does look a lot prettier when it comes from tubes, which the artistic side of me enjoys deeply.
I chose PP because I enjoy the beauty of tubes and my experiences with PP amps has led me to the 7591 as the best sounding tube for my ears. I've lived with KT66s, 6L6GCs, 7591s and EL34s, all in fully restored and correctly operating amps and I found the 7591s to have the detail, clarity and bass of the 6L6 family but with the full mid-range of the EL34s.
I think in the end the question really comes down to power, complexity and cost.
A SET is in some ways simpler to build, but on the backside the advantage of simplicity is offset by the cost of building or buying speakers to suit.
A PP is in some ways the exact opposite. The advantage of using less efficent speakers is offset by the more complicated building of a PP amp.
Either one can give great results. The question is which solution works best for you?
Best,
mr mojo
Konnichiwa,
The room can cause 40db swing and is not commonly called tone control.
And I repeat, +/-2db at (say) 50Hz require only a few inch displacement of listener or speaker displacement, so the few db shift caused by using an SE amplifier can usually be adjusted for.
Let us just say that you dislike SE Amplifiers because your worldview is based on the assumption that modern style engineering must invariably be better, so if people still like the old stuff it must be because they "enjoy" distortion.
For me, I have no prejudices on the subject, never had any, so I pragmatically use whatever does the job best for my personal use.
Sayonara
SY said:
The room can cause 40db swing and is not commonly called tone control.
And I repeat, +/-2db at (say) 50Hz require only a few inch displacement of listener or speaker displacement, so the few db shift caused by using an SE amplifier can usually be adjusted for.
Let us just say that you dislike SE Amplifiers because your worldview is based on the assumption that modern style engineering must invariably be better, so if people still like the old stuff it must be because they "enjoy" distortion.
For me, I have no prejudices on the subject, never had any, so I pragmatically use whatever does the job best for my personal use.
Sayonara
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