I have had about 4 or 5, audionote, diyhifisupplys, and a few others, whilst not being bad, they just really haven't sounded as they are touted to.
They were quite clear, transparent on acoustic music, but limited power and bass, in fact, I am wondering if the output transformers do limit the capabilities too. They DID sound a bit slow relative to low output impedance amps.
Are they worth the trouble?
They were quite clear, transparent on acoustic music, but limited power and bass, in fact, I am wondering if the output transformers do limit the capabilities too. They DID sound a bit slow relative to low output impedance amps.
Are they worth the trouble?
Very good question indeed. Your assessment of the sound produced by mid priced SET amps is very similar to my own. They seem to sound great to people with sympathetic music tastes but are definitely not for everyone.
In my view this has not much to do with inherent limitations of output transformers or output valves but is mostly the result of cost-cutting.
IME a good sounding SET amp requires high qualty (and heavy) independent power supplies for each stage. Ideally this means at least 4 power transformers with assosiated chokes and caps. If you separate the heater supplies add a few more pieces of iron.
I have also never really liked a driver stage without iron - either choke or transformer loaded.
Do everything properly and you are easily looking at a part cost running into several Ks. Plus you need suitable speakers.
So, how can a kit amp costing $799 sound any good into a pair of LS3/5A
They were quite clear, transparent on acoustic music, but limited power and bass, in fact, I am wondering if the output transformers do limit the capabilities too. They DID sound a bit slow relative to low output impedance amps.
Are they worth the trouble?
I do think it is worth the trouble. When you use output transformers that are of better quallity they will have better frequentie range. For example if you wanna play SACD it is a must, becausr SCAD and also DVD - audio play with higher frequentie's, if you're output transformers aren't made to let trough these higher frequentie's it is almost useless to play SACD. Because you will not hear that details that make SACD different then CD. But that's my thoughts about it.
In holland we have output transformers that have amorfe material in the core. I don't know what it is called in englisch. Maybe the same, But that material makes a lot of diffence, but is very expensive. Other way is to have output transforemers with a lamel thikness of less then 0,05 mm. What's difference? More low bas, and higher frequentie sounds, also more dept ans less sharpness. The best to that is bigger transformers with more windings and thinner lamels. then you can have an ouput between 20 hz to 100 kHz In holland we have a transformer builder that makes them winded with silver. Last but even important. A well build ouput transformer can pretty good prevent a hummmm on you're speakers. That's just a must!
Next to that, a power transformer can also make a big diffence. First of al. is net filtering. A well build power transformer can filter all frequenties above 50Hz. Other net garbage will not get trough!
Hope this is will help you. Sorry for the spelling.
Greetz Jan Pieter,
Are they worth the trouble?
I do think it is worth the trouble. When you use output transformers that are of better quallity they will have better frequentie range. For example if you wanna play SACD it is a must, becausr SCAD and also DVD - audio play with higher frequentie's, if you're output transformers aren't made to let trough these higher frequentie's it is almost useless to play SACD. Because you will not hear that details that make SACD different then CD. But that's my thoughts about it.
In holland we have output transformers that have amorfe material in the core. I don't know what it is called in englisch. Maybe the same, But that material makes a lot of diffence, but is very expensive. Other way is to have output transforemers with a lamel thikness of less then 0,05 mm. What's difference? More low bas, and higher frequentie sounds, also more dept ans less sharpness. The best to that is bigger transformers with more windings and thinner lamels. then you can have an ouput between 20 hz to 100 kHz In holland we have a transformer builder that makes them winded with silver. Last but even important. A well build ouput transformer can pretty good prevent a hummmm on you're speakers. That's just a must!
Next to that, a power transformer can also make a big diffence. First of al. is net filtering. A well build power transformer can filter all frequenties above 50Hz. Other net garbage will not get trough!
Hope this is will help you. Sorry for the spelling.
Greetz Jan Pieter,
In your case clearly not. Because you have listened and found them lacking in some aspects you find important.
It is important to know that SE amplifiers specifically need to have speakers that suit them. I.e. that cater to their weaknesses.
Increasingly I am finding that to get the music reproduced the way you want it you need the right combination. Thus discussing a topology out of a particular contest is pointless.
I'll give you an example. a BrianGT based gainclone I built sounds great on my Prometheus..but simply does not have the current (I find) to drive my CSS FR125 speakers. The Rod Elliot P3A had what it takes to make them come alive.
Don't forget to compensate your speakers impedance.
Most speakers present a complex load to the amp and with non-low output impedance amps, this can affect the frequency response and dynamics coming from your speakers in accordance with their impedance variations. There is no logical reason to let this happen.
Most speakers present a complex load to the amp and with non-low output impedance amps, this can affect the frequency response and dynamics coming from your speakers in accordance with their impedance variations. There is no logical reason to let this happen.
Re: Re: do 300b amps really sound any good?
Amorphous material? One commercial form I have come across is called metglas. It is made by cooling the metal from liquid to solid at something like 10,000 degrees per second so the solid metal does not have a grain structure. It is used for tape-wound toroids in SMPS's.
janpieterelbaas said:
Amorphous material? One commercial form I have come across is called metglas. It is made by cooling the metal from liquid to solid at something like 10,000 degrees per second so the solid metal does not have a grain structure. It is used for tape-wound toroids in SMPS's.
analog_sa said:
*heh*. That only proves that some of these 300B n00bs are only going for looks and labels, and don't know how to distinguish a bad sounding amp from a good one (unless their guru accidentally declares a good sounding amp holy).
'ah, this transformer has silver wire, so *it must be good*'
alex278 said:
*heh*. That only proves that some of these 300B n00bs are only going for looks and labels, and don't know how to distinguish a bad sounding amp from a good one (unless their guru accidentally declares a good sounding amp holy).
'ah, this transformer has silver wire, so *it must be good*'
May be some people do, but i think that most people that are building there own tube amps do it to get e better sound. However sound is personal. I can make a silver wired amp with silver secundairy" ?" wired output transformers, spent 5000 dollar on it! that should sound great. But in the end it is all personall. Another person that's listens to my set can say i don't like the sound of it. It;s to pointy, sharp ore something els. I think that's ok. I have to listen to it the most! I go to a severall audio shows. And sometimes ( Also depending on the setup and acousics of the room ) Hifi Stes that cost a fortune just don't sound right in my ears, while others think it's the best! Well, that's just the reason why there so many different setups and also why we are always lokking for better! That's a good thing. And for DIY it leeds to innovation!
Audionote kit1
After over twenty years of experimenting with many different amps.
My preferred sounding tube would be the 300b.
In my 8wpc audionote kit1 matched with a pair of 102db efficiency Cornwall Klipsch speakers they are a magical experience with my vinyl setup.
The 300b has this seductive elegant transparency rarely found in other tubes. Many tubes would have better bass or even better highs but it’s the overall sound of the 300b that keeps you listening.
Well I guess it depends on your taste.
After over twenty years of experimenting with many different amps.
My preferred sounding tube would be the 300b.
In my 8wpc audionote kit1 matched with a pair of 102db efficiency Cornwall Klipsch speakers they are a magical experience with my vinyl setup.
The 300b has this seductive elegant transparency rarely found in other tubes. Many tubes would have better bass or even better highs but it’s the overall sound of the 300b that keeps you listening.
Well I guess it depends on your taste.
has anyone listened to the WAVAC EC-300b? I haven't. But the reviews seems to put it as one of the best 300B amplifier ever.
But looking at the design, it has a few things that defies some of the general wisdoms.
1) there is no fancy power supply. Only one power transformer supplying everything.
2) solid state rectification for the 300b filament with what looks like a simple one stage 33,000uF for each channel
3) For B+ solid state diodes + CLC filter (I cannot make out the exact values)
Maybe the magic is in the circuit? I don't have the schematic, but so far I can tell, it is:
- triode wired WE435A + 6L6 with interstage.
- cathode biased 300B. there are 2x 1.5k 10W resistors in parallel near the cathode hum pot
This is a photo I found online:
GE5A4603-4 | Wavac EC300B Innards | Zerung | Flickr
But looking at the design, it has a few things that defies some of the general wisdoms.
1) there is no fancy power supply. Only one power transformer supplying everything.
2) solid state rectification for the 300b filament with what looks like a simple one stage 33,000uF for each channel
3) For B+ solid state diodes + CLC filter (I cannot make out the exact values)
Maybe the magic is in the circuit? I don't have the schematic, but so far I can tell, it is:
- triode wired WE435A + 6L6 with interstage.
- cathode biased 300B. there are 2x 1.5k 10W resistors in parallel near the cathode hum pot
This is a photo I found online:
GE5A4603-4 | Wavac EC300B Innards | Zerung | Flickr
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Yeah, maybe
What cannot be denied though is the extreme sophistication and sexiness of the exterior. Even the cheap skate concept of terminals facing upwards appears purposeful and elegant. It's like an amazingly sexy woman: who'd dare point out she's thick as a brick?
300B amplifiers with good bass are possible, but there are a few things in the chain that need to be right:
- appropriate speakers
- oversized output transformer
- low impedance power supply
My 300B-SE amplifiers sound superb, even with loud bass.
- speakers are designed for amplifiers with modest damping factor (Lynn Olson ME2)
- OT is Sowter SA08: POWER (For 0.5 % Distortion at 20 Hz) is 25W rated
SA08 SINGLE ENDED OUTPUT TRANSFORMER
expensive - but superb quality - a lifetime of good sound from these makes the cost really acceptable.
- power supply uses SiC schottlky diodes and large, top-quality 550V caps: Kemet ALS60 series 820µF 550V
The changes to the power supply do not spoil the delicacy of playing chamber music.
- appropriate speakers
- oversized output transformer
- low impedance power supply
My 300B-SE amplifiers sound superb, even with loud bass.
- speakers are designed for amplifiers with modest damping factor (Lynn Olson ME2)
- OT is Sowter SA08: POWER (For 0.5 % Distortion at 20 Hz) is 25W rated
SA08 SINGLE ENDED OUTPUT TRANSFORMER
expensive - but superb quality - a lifetime of good sound from these makes the cost really acceptable.
- power supply uses SiC schottlky diodes and large, top-quality 550V caps: Kemet ALS60 series 820µF 550V
The changes to the power supply do not spoil the delicacy of playing chamber music.
"do 300b amps really sound any good?"
Yes, one look at the curves of the Western Electric 300B tube and you can see why. https://www.westernelectric.com/static/library/specifications/tubes/300B.pdf
Why would it not sound good? Limited power as SE needing efficient speakers of course. Are there other tubes or SS devices that sound almost as good, of course. I just finished a SE KT-88 amplifier that sounds fantastic as well. Still love my SE 300B amplifier. Not for everyone? Of course not. Name one amplifier that is.
Yes, one look at the curves of the Western Electric 300B tube and you can see why. https://www.westernelectric.com/static/library/specifications/tubes/300B.pdf
Why would it not sound good? Limited power as SE needing efficient speakers of course. Are there other tubes or SS devices that sound almost as good, of course. I just finished a SE KT-88 amplifier that sounds fantastic as well. Still love my SE 300B amplifier. Not for everyone? Of course not. Name one amplifier that is.
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