Hi all,
Currently, I am hooking up my simple single stage common cathode 6h30 preamp to a SS power amp (yamaha MX-2), and enjoying it (I suppose the coupling caps are being broken in gradually)
I am looking to go another step now
in building a tube power amp. I have been reading up on some of the common types and configurations but still cannot decide. I am leaning on a simple EL84 PP, but some warned me that it will not sound as good on vocals as SETs. Unfortunately, I have Infinity primus 360s, which are speced at 93db but Stereophile measured them at 91+db only. With my SS power amp, I do have the punch that I like, and I was warned that with SETs, I will lose significant portion of the punch.
I hope to get some advice, comments, feedback form you guys to come to a good compromise that is still relatively simple and safe to build.
thanks!
Currently, I am hooking up my simple single stage common cathode 6h30 preamp to a SS power amp (yamaha MX-2), and enjoying it (I suppose the coupling caps are being broken in gradually)
I am looking to go another step now
in building a tube power amp. I have been reading up on some of the common types and configurations but still cannot decide. I am leaning on a simple EL84 PP, but some warned me that it will not sound as good on vocals as SETs. Unfortunately, I have Infinity primus 360s, which are speced at 93db but Stereophile measured them at 91+db only. With my SS power amp, I do have the punch that I like, and I was warned that with SETs, I will lose significant portion of the punch.I hope to get some advice, comments, feedback form you guys to come to a good compromise that is still relatively simple and safe to build.
thanks!
I would suggest an EL34 PP UL that will give you about 30W and plenty of punch. There are atleast 3 or 4 good ckts out there (read the EL34 schematic confusion thread).
As far as kits go the ELLA Consonance is nice as it can take 6550 and KT88 as well.
My brother in law who lives in Singapore has built this kit and i have heard it with the 6550 and EL34 (different driver tube) and prefered the 6550.
Lastly at 91db even an EL84 PP UL can give you enough. Tube watts sound louder than SS watts. dont know why.
As far as kits go the ELLA Consonance is nice as it can take 6550 and KT88 as well.
My brother in law who lives in Singapore has built this kit and i have heard it with the 6550 and EL34 (different driver tube) and prefered the 6550.
Lastly at 91db even an EL84 PP UL can give you enough. Tube watts sound louder than SS watts. dont know why.
"Tube watts sound much louder than SS watts" - for sure.
Putting clipping aside, I don't know if it is related to high-ish 2nd (and higher even) order distortion(s). Tube amps sound much smoother, rounder, fatter, and thicker than SS amps, the later usually measure substantially better THD figures even though the odd order distortion may be higher.
I have this recent experience with my 12B4A line stage preamp. When I initially used a pair of low quality fake Philips as filter caps the sound stage was very big but very muddy. The bass was very heavy. I guess some ringing in the lower frequencies in the PSU might have caused that. Replacing the fake Philips with genuine Panasonic ED and Vishay the sound was substantially cleaner but less thick. I noticed that I had to turn the volume control up 20% more to get the same sound level. In the latest event I changed all filter caps to Panasonic TSHA (with a 20uF ICW Clarity Caps in parallel with the last TSHA cap) and installed a snubber on the secondary winding to damp the resonance caused by the leakage inductance (measured by the transformer manufacturer) and the capacitance of the diode bypass caps, again the sound is slightly cleaner possibly due to reduced ringing and I need to turn the volume control up another 5-10% to get the same sound level. In those cases, it was distortion (undamped resonances) that cause the louder sound.
Is it because additional even order harmonics on top of the signals causing the louder sound in tube amps? Obviously tube amps usually sound quite thick and warm. While adding presence, "realism" to the music it is sometimes bigger than life. My tube friends love playing female voices or pianos with Audio Note preamps, 300B and Rogers LS3/5A and said the voices and pianos were real. I would say the sound was sweet and very nice but in no way real.
I certainly don't mind having a little bit of 2nd order distortions and indeed, I much prefer tube preamps to SS or IC preamps. Tube preamps are much nicer to the ears and can create an illusion of realism. It is like cooking dishes with a bit of spices - the original tastes are still there but now with added flavours. It is nice. Without spices the food could be fairly tasteless, but if too much are added they will destroy the original tastes. This leads me to believe that there is no such a thing as the ultimate HiFi and it is really subject to personal tastes like our preference for food. I
'd be open minded.
Regards,
Bill
Putting clipping aside, I don't know if it is related to high-ish 2nd (and higher even) order distortion(s). Tube amps sound much smoother, rounder, fatter, and thicker than SS amps, the later usually measure substantially better THD figures even though the odd order distortion may be higher.
I have this recent experience with my 12B4A line stage preamp. When I initially used a pair of low quality fake Philips as filter caps the sound stage was very big but very muddy. The bass was very heavy. I guess some ringing in the lower frequencies in the PSU might have caused that. Replacing the fake Philips with genuine Panasonic ED and Vishay the sound was substantially cleaner but less thick. I noticed that I had to turn the volume control up 20% more to get the same sound level. In the latest event I changed all filter caps to Panasonic TSHA (with a 20uF ICW Clarity Caps in parallel with the last TSHA cap) and installed a snubber on the secondary winding to damp the resonance caused by the leakage inductance (measured by the transformer manufacturer) and the capacitance of the diode bypass caps, again the sound is slightly cleaner possibly due to reduced ringing and I need to turn the volume control up another 5-10% to get the same sound level. In those cases, it was distortion (undamped resonances) that cause the louder sound.
Is it because additional even order harmonics on top of the signals causing the louder sound in tube amps? Obviously tube amps usually sound quite thick and warm. While adding presence, "realism" to the music it is sometimes bigger than life. My tube friends love playing female voices or pianos with Audio Note preamps, 300B and Rogers LS3/5A and said the voices and pianos were real. I would say the sound was sweet and very nice but in no way real.
I certainly don't mind having a little bit of 2nd order distortions and indeed, I much prefer tube preamps to SS or IC preamps. Tube preamps are much nicer to the ears and can create an illusion of realism. It is like cooking dishes with a bit of spices - the original tastes are still there but now with added flavours. It is nice. Without spices the food could be fairly tasteless, but if too much are added they will destroy the original tastes. This leads me to believe that there is no such a thing as the ultimate HiFi and it is really subject to personal tastes like our preference for food. I
'd be open minded.
Regards,
Bill
navin said:
It's the nature of SS devices to clip viciously. (This is part of the reason why they make such good digital devices.) Add the necessary NFB to linearize them for audio, and that exaggerates the clipping behaviour. This, in turn, generates lots of disagreeable high order harmonics. VTs, when overdriven, don't hit the rail like that. Instead, they sort of "sneak up" on the rail, and have to be overdriven considerably to generate those horrible-sounding harmonics. Audio signals tend to spend a lot of time at some low average value with transients that can be up to ten times higher than that average.
So you have to run that 100W SS amp considerably below 100W in order to have enough head room to accommodate the fast rising transient without clipping. Due to how VTs clip, a transient can cause clipping without your even noticing it. (unless it's built like a SS amp: lots of NFB). Therefore, the 30W VT amp can run at a higher average that makes it sound louder than a more powerful SS amp.
How about something like this?http://www.diyparadise.com/simpleel84.html
Should be quite simple since I already have a 6h30 preamp right? Will this work?
Should be quite simple since I already have a 6h30 preamp right? Will this work?
pengboon said:
With your Infinity speakers, the match is POOR. As I said over on AA, there are significant damping factor considerations.
If a SIMPLE tubed circuit, with a typically modest damping factor, is to be employed, you will need to acquire a different pair of speakers.
pengboon said:How about 300B SET driven by 6SN7? I came across this kit this evening, comes with Permalloy output transformers too...
IMO, a 300B SET amp is a VERY poor match for your Infinity speakers. Both power O/P and damping factor are INADEQUATE.
Triode wired PP EL34s operating in "shallow" Class "A" will provide enough power, while being relatively simple. What I have in mind is "El Cheapo" like, with higher O/P power. Fixed, as opposed to cathode, bias will be employed. The gain of the 12AT7 splitter/driver is lowish for driving EL34s and a NFB loop. However, your 6n30p line stage will provide the extra gain that's needed.
Can you source O/P trafos suitable for use with EL34s in Singapore? Ultra linear taps are OK, but not necessary.
In regard to the "tube watts are louder than SS watts" statement. Music has at least a 10 db peak to average ratio, some music approaches 20 db. This means that you need 10 to 100 times more peak power than average power to totally avoid clipping. What has this got to do with the tubes VS SS debate. It is true that most SS amps sound gross when they clip. This has more to do with the heavy feedback than the choice of active devices. A zero feedback tube amp can actually operate slightly into clipping without being detected by most listeners. Don't believe it? Hook up your scope, crank up your amp without looking until you hear audible distortion, then back up until the distortion is gone. Check the scope, you will find that there is still clipping on bass transients.
As far as the 91 db speakers, it depends on your listening environment, your choice of music, and how loud you want to get. I have Yamaha NS-10's, 87 db effiecient. I have 3 different tube amplifiers, a 8 watt 300B SE, a 25 watt 300B P-P, and a 40 watt 845 SE. I find myself listening to the 300B SE most often, and I like rock music. It does do the best job of vocals, piano, and similar music. For really dynamic music, the 300B P-P does best. It does have that punch that I have yet to find in an SE amp.
If you can, try to listen to the different types of tube amps. There really is a difference between the sound of a SE amp and a push - pull amp. It is hard to describe, and depends a lot on your personal tastes.
I must warn you that building tube amps can be an addictive hobby. Most people can't build just one. So, build an amp that fits your needs, but most important, pick one that you can finish, and get working. Nothing can ruin a new hobby faster than spending a lot of time and money, and nothing works.
As far as the 91 db speakers, it depends on your listening environment, your choice of music, and how loud you want to get. I have Yamaha NS-10's, 87 db effiecient. I have 3 different tube amplifiers, a 8 watt 300B SE, a 25 watt 300B P-P, and a 40 watt 845 SE. I find myself listening to the 300B SE most often, and I like rock music. It does do the best job of vocals, piano, and similar music. For really dynamic music, the 300B P-P does best. It does have that punch that I have yet to find in an SE amp.
If you can, try to listen to the different types of tube amps. There really is a difference between the sound of a SE amp and a push - pull amp. It is hard to describe, and depends a lot on your personal tastes.
I must warn you that building tube amps can be an addictive hobby. Most people can't build just one. So, build an amp that fits your needs, but most important, pick one that you can finish, and get working. Nothing can ruin a new hobby faster than spending a lot of time and money, and nothing works.
Eli Duttman said:
Eli, I'm not sure what's going on at AA now, but this forum's format seems easier to use. Anyway, I find my current setup, a little boomy on the bass, could be room nodes, so relistically speaking, I really do not mind a little less punch and bass. With that in mind, would you change your recommendations?
p.s. If it helps, I've heard my speakers with a Sun Audio 2A3 SET (3.5wpc), and it sounds OK to me wrt the low end, probably not as punchy as my SS, but not as bad as I would imagine. Somewhere in between would suffice for me...
tubelab.com said:
I do not listen to rock (nothing against it) more jazzy, vocals, a little bit of pop, sometimes dynamic stuff. Listening environment is smalish apartment living room. With my current 6h30 pre and SS poweramp, I hardly turn the vol knob more than 20 degs. I've heard different amps, just that they are in different setups, so I find it difficult still to figure them out...
My recommendation for PP triode wired EL34s with loop NFB stands. That gives you enough power for transients, decent voice coil control, and a relatively easy build. Run the EL34s with 400 or so V. on the plate and an idle current of 40 mA. EL34 screen grids are tough, so tie them to the plates with 100 Ohm resistors of the "flavor" you like best.
The PP tube amp WILL be between the SS and the SET.
While SET is "best" for midrange, the PP tube amp will not be far behind.
The 211 or 845 (I have built both) is probably the best of ths SE's, although I will probably have a different opinion after my 833A SE is done. However due to the high voltages and costs involved, I would not think that this is a good place to start.
The triode wired PP EL-34 is a good place to start, although you may not need or want feedback. It depends on your speakers, room layout, and personal tastes. It is pretty simple to try it both ways. A P-P amp has dynamic qualities that I haven't been able to get in an SE, although I keep trying (the 833A). Most of my early amps were P-P, then I caught the SE bug, and have built about 10 of those.
If you have heard some SE amps and you didn't immediately get this unquenchable desire to get one, build the P-P while you still have a chance. I caught the bug, first I built a 45SE, then a 2A3SE, then several 300B SE's then a couple of triode wired sweep tube SE's (another excellent possibillity), then the 211 / 845 SE, and now the 833A SE. That has to be the last one, I am going to make some P-P after that.
The triode wired PP EL-34 is a good place to start, although you may not need or want feedback. It depends on your speakers, room layout, and personal tastes. It is pretty simple to try it both ways. A P-P amp has dynamic qualities that I haven't been able to get in an SE, although I keep trying (the 833A). Most of my early amps were P-P, then I caught the SE bug, and have built about 10 of those.
If you have heard some SE amps and you didn't immediately get this unquenchable desire to get one, build the P-P while you still have a chance. I caught the bug, first I built a 45SE, then a 2A3SE, then several 300B SE's then a couple of triode wired sweep tube SE's (another excellent possibillity), then the 211 / 845 SE, and now the 833A SE. That has to be the last one, I am going to make some P-P after that.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.