ray_moth said:Chris,
I am ready to face the slings and arrows of outraged even-order-harmonic buffs - er, SETsters. No offence, really!
Joking aside, not wishing to ruffle any feathers but it is easier to succeed with PP than with SET, especially for a relative newcomer to tubes - to build a PP amp and get it working and to find speakers that will sound OK with it.
Haha, I love Hamlet!
I think what ray meant was not the build itself, but rather easier to succeed with PP given the speaker in question.
My golly, how can you beat a SET in assembly... two resistors, one capacitor, one output transformer, with the assumption that power supply is common and not in the picture.
With PP, you have to worry about the driver
the phase splitter 
the output topology (UL, Triode-connection, Pentode-connection) 
so in the end, it is more work 
My golly, how can you beat a SET in assembly... two resistors, one capacitor, one output transformer, with the assumption that power supply is common and not in the picture.
With PP, you have to worry about the driver
the phase splitter the output topology (UL, Triode-connection, Pentode-connection) so in the end, it is more work 
arnoldc said:I think what ray meant was not the build itself, but rather easier to succeed with PP given the speaker in question.
My golly, how can you beat a SET in assembly... two resistors, one capacitor, one output transformer, with the assumption that power supply is common and not in the picture.
With PP, you have to worry about the driver
That's exactly what I was thinking (ever since I have been reading these forums, I know what all that stuff is now
)So, a PP is more likely to be a higher quality on a wider varitey of music? Is this simply because of the generally higher output power? or because of the harmonics produced by a push-pull system (odd order harmonics?), or the cancelation of tube noise?
alex, that is somethig that is so subjective. My musical preferences ranges from Classical to Heavy Metal and Dance/Trance.
My most powerful amp is a 5-watt 300B which was borrowed by a friend driving his Avant Garde Duo. I am now left with a 45 (1.something watts) and 2A3 (3 watts). My speakers are somewhat efficient for these amp. They're DIY made up of Altec 406-8Y, Oxford Horns and Fostex tweets. I can tell you with these speakers, I can rock!
Given your speakers, and your listening preferences which you have stated, it might be best to start off with a PP amp project. I am afraid that you might go SET (for simplicity) and then get disappointed in the end, due to lack of power, for your speakers.
Now, whethere SET is better than PP (vis-a-vis) only *your* ears can decide.
Cheers!
My most powerful amp is a 5-watt 300B which was borrowed by a friend driving his Avant Garde Duo. I am now left with a 45 (1.something watts) and 2A3 (3 watts). My speakers are somewhat efficient for these amp. They're DIY made up of Altec 406-8Y, Oxford Horns and Fostex tweets. I can tell you with these speakers, I can rock!
Given your speakers, and your listening preferences which you have stated, it might be best to start off with a PP amp project. I am afraid that you might go SET (for simplicity) and then get disappointed in the end, due to lack of power, for your speakers.
Now, whethere SET is better than PP (vis-a-vis) only *your* ears can decide.
Cheers!
I will say that the power supply is much simpler for a P-P than a SET. The biggest problem with beginners and SET type amps are hum and THD. The extra power you get from a P-P design is easier to deal with as well.
A high fidelity SET output transformer is going to be a lot more expensive than an equivalent P-P transformer. May as well do a P-P. You are not exactly breaking new ground here either. There are many examples of both types that will work if you build them as they are meant to be. A pictorial helps a lot too if you build a heathkit or Eico clone (or any other similar type that had kit instructions).
-Chris
A high fidelity SET output transformer is going to be a lot more expensive than an equivalent P-P transformer. May as well do a P-P. You are not exactly breaking new ground here either. There are many examples of both types that will work if you build them as they are meant to be. A pictorial helps a lot too if you build a heathkit or Eico clone (or any other similar type that had kit instructions).
-Chris
Hi Arnold,
No problem. With a SET amp, any supply ripple to the output will have little attenuation to the transformer. Therefore the standards that a power supply for a SET amp are far more demanding.
With a P-P amp, as long as the output tubes are balanced any reasonable amount of supply ripple is canceled out in the transformer. Just like the 2nd harmonics. Neat huh? Also, in most P-P amps the outputs are run in class AB1 with cutoff. That means the average current is lower for the same output power per tube. You will get far more power too.
Since there is little DC component in the output transformer core (cancels too), it can be smaller without saturation for equivalent power output.
As you say, some people may prefer the sound of a SET amp. P-P amps became popular for a reason, not all of which were engineering and accounting concerns. But there are many factors that will affect the sound, so comparing fairly is difficult.
There are others here that understand tube amp construction and design better than I do.
-Chris
No problem. With a SET amp, any supply ripple to the output will have little attenuation to the transformer. Therefore the standards that a power supply for a SET amp are far more demanding.
With a P-P amp, as long as the output tubes are balanced any reasonable amount of supply ripple is canceled out in the transformer. Just like the 2nd harmonics. Neat huh? Also, in most P-P amps the outputs are run in class AB1 with cutoff. That means the average current is lower for the same output power per tube. You will get far more power too.
Since there is little DC component in the output transformer core (cancels too), it can be smaller without saturation for equivalent power output.
As you say, some people may prefer the sound of a SET amp. P-P amps became popular for a reason, not all of which were engineering and accounting concerns. But there are many factors that will affect the sound, so comparing fairly is difficult.
There are others here that understand tube amp construction and design better than I do.
-Chris
In most cases the output impedance of a SE amplifier is higher, and no feedback is used to stabilize the design. This means that the sound is quite dependent on the interaction between the amp and the speaker. Speakers that have an impedance that varies a lot over the audio frequency range generally do better with a P-P amp. These are generalizations of course.
I have built a lot of tube amps over the years. I also like a lot of different music. So my current setup has 3 different amps. Two SE amps and a P-P amp. If I want to play Jimi loud, or shake the walls with techno, I use my 30 watt P-P amp. It does not use feedback, but has a sound that I have not been able to duplicate in a SE amp. The 6AV5 UL with cathode feedback comes real close though. The SE amps have more detail and do vocals, piano, sax, and a lot of music in a way that a P-P amp just can't.
Either way if you build an amp yourself it will sound good! It just works that way. Pick a design that you can finish. The worst way to kill a new hobby is to start with a complicated project, and never finish it. You will improve on it, and eventually build another one.
I was fortunate enough to go to high school in a time when you could get enough parts to build a decent amp by going to the trash dump! I had built several guitar amps and a couple of stereos by the time that I graduated. Those days are gone forever though.
I have built a lot of tube amps over the years. I also like a lot of different music. So my current setup has 3 different amps. Two SE amps and a P-P amp. If I want to play Jimi loud, or shake the walls with techno, I use my 30 watt P-P amp. It does not use feedback, but has a sound that I have not been able to duplicate in a SE amp. The 6AV5 UL with cathode feedback comes real close though. The SE amps have more detail and do vocals, piano, sax, and a lot of music in a way that a P-P amp just can't.
Either way if you build an amp yourself it will sound good! It just works that way. Pick a design that you can finish. The worst way to kill a new hobby is to start with a complicated project, and never finish it. You will improve on it, and eventually build another one.
I was fortunate enough to go to high school in a time when you could get enough parts to build a decent amp by going to the trash dump! I had built several guitar amps and a couple of stereos by the time that I graduated. Those days are gone forever though.
Hi Tubelab,
That's what I'm trying to say. Build something easy and small. Just get down and do it or it'll never get done.
You lucky fella! My wife made me throw out all my "supplies" which she viewed as junk. You have an entire warehouse ! 
Do you ever get distracted with all those great projects just waiting?
-Chris
That's what I'm trying to say. Build something easy and small. Just get down and do it or it'll never get done.
You lucky fella! My wife made me throw out all my "supplies" which she viewed as junk.
You have an entire warehouse ! Do you ever get distracted with all those great projects just waiting?-Chris
I'm like you guys. I have all these parts collected and am always getting distracted with ideas how I can put them to use in a project, which is after all what they were collected and stored for in the first place. I am fortunate not to have a spouse making me throw out my long collected treasure, but moves have been responsible for leaving behind some stuff that has caused self-critisizm since.
This latest idea to make a 1.5 kW tube amp with a pair of 450TH triodes is a great example of something I have no real need for but it seems like a cool idea to make as a project entirely enabled because I have the parts. It is also inspired by the acceptance that if I don't get a round tuit now I will not likely ever do anything of value or interest with this 'treasure'. I'm quickly running out of time on my clock. Would I be spending big coin now to buy the parts to make such an amp? No way.
This latest idea to make a 1.5 kW tube amp with a pair of 450TH triodes is a great example of something I have no real need for but it seems like a cool idea to make as a project entirely enabled because I have the parts. It is also inspired by the acceptance that if I don't get a round tuit now I will not likely ever do anything of value or interest with this 'treasure'. I'm quickly running out of time on my clock. Would I be spending big coin now to buy the parts to make such an amp? No way.
Yeah, like I really need a 200 watt SE guitar amp. I have all of the parts, but:
This seems to be the hard part for many of us. I can whip together a prototype amplifier design in a really short time. It is not uncommon for me to go from dumb idea to working prototype amplifier in a few hours (single channel, external bench type power supplies)! There are currently 3 working amplifier prototypes on my Tubelab breadboard right now, and a fourth made with clip leads on the other bench. I would like at least 2 of them to become real amplifiers, but it will probably be months before I build an enclosure to put them in.
Alexmoose,
Despite some deviations from the thread topic it is not lost. In my experience, and remembering how I was when I was young, I highly recommend going with a P-P design right now for a first tube amp. As has been mentioned it will be more forgiving of potentially weird loudspeaker load issues and will have more power for any particular choice of ouptut tube type. A good output xfmer is much cheaper per watt. P-P amps are not harder to make than SE.
I used to like my music pounding loud. Now I still like to play fairly loud occasionally but my emphasis in the past few years has been on ultimate realizm of reproduction to the original event (so forget music recordings that are full of compression, meaning forget rock or popular type music). This has opened my range of music experience into jazz format in a big way. I like my tone served with slam and this is hard to do with a SET amp and won't happen with one or two SET watts on 90 dB speakers.
Build a P-P amp with at least 15 or 20 watts per channel and have some fun! P-P 6L6's would be great for you IMO and they are not expensive. Some derivative of the Williamson amp is good but I think I'd recommend going with the classic Dynaco MK-II amplifier circuit for it's great performance and also pure simplicity. I made one back when I was in my late teens and I still have it today. I used 5R4 rectifier, two 6CA7/EL34 output tubes in ultra-linear, a 6AN8A functioning as the pentode input amp and triode concertina phase splitter/driver in the same tube. Total three tubes per channel plus the common rectifier tube. For output iron I went expensive Hammond 1726's but you can go much cheaper today. I think I'd look at the Edcor transformers, if not a tried and true easily sourced Hammond.
Despite some deviations from the thread topic it is not lost. In my experience, and remembering how I was when I was young, I highly recommend going with a P-P design right now for a first tube amp. As has been mentioned it will be more forgiving of potentially weird loudspeaker load issues and will have more power for any particular choice of ouptut tube type. A good output xfmer is much cheaper per watt. P-P amps are not harder to make than SE.
I used to like my music pounding loud. Now I still like to play fairly loud occasionally but my emphasis in the past few years has been on ultimate realizm of reproduction to the original event (so forget music recordings that are full of compression, meaning forget rock or popular type music). This has opened my range of music experience into jazz format in a big way. I like my tone served with slam and this is hard to do with a SET amp and won't happen with one or two SET watts on 90 dB speakers.
Build a P-P amp with at least 15 or 20 watts per channel and have some fun! P-P 6L6's would be great for you IMO and they are not expensive. Some derivative of the Williamson amp is good but I think I'd recommend going with the classic Dynaco MK-II amplifier circuit for it's great performance and also pure simplicity. I made one back when I was in my late teens and I still have it today. I used 5R4 rectifier, two 6CA7/EL34 output tubes in ultra-linear, a 6AN8A functioning as the pentode input amp and triode concertina phase splitter/driver in the same tube. Total three tubes per channel plus the common rectifier tube. For output iron I went expensive Hammond 1726's but you can go much cheaper today. I think I'd look at the Edcor transformers, if not a tried and true easily sourced Hammond.
Okay, I think you guys have all convinced me that PP is the way to go for now, SE might be this summer! I looked at the Schematic for the Dynaco Mark II, looked simple enough, however I need to know what powersupply to use? alot of these name-brand amplifiers use freaky voltages, any other PP design suggestions are welcome
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