Pink,
Do you think that the 50VA Toroid was overkill? Was there too much heat or noise?
Do you think that the 50VA Toroid was overkill? Was there too much heat or noise?
x-Cans V2 PSU completed!
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Dreamslacker
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Hmm... So the filter on the IEC's not good and the toroid you have is no better than a laminated core transformer?
I always thought the Toroidals are better. Maybe it's cos I've always seen Lindbergh toroids only.
But I must say the height of toroids make them awfully tempting to use.
| Originally posted by PinkFloyd Hi The 50VA toroidal is going to be replaced with a 20VA laminated transformer and the IEC filter is going to be binned. Full explanation to follow. The PSU shown at http://freespace.virgin.net/rock.grotto will "not" damage your x-ponent in any way but it is not the "optimal" power supply for the X-can V2. It's a huge improvement over the wall wart but I have designed the Ultimate PSU which Makes the X-can V2 really sing. It turns out that the laminated standard tranny performs better than the toroid and , indeed, has far better tolerances... Watch this space Pinkie |
Hmm... So the filter on the IEC's not good and the toroid you have is no better than a laminated core transformer?
I always thought the Toroidals are better. Maybe it's cos I've always seen Lindbergh toroids only.
But I must say the height of toroids make them awfully tempting to use.
PinkFloyd
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Quote:
I'm sorry Dreamslacker but I didn't explain what I meant correctly.
I was reading somewhere that to get the best out of any audio equipment it's essential to use an "audio transformer" as these have a much higher bandwidth than a normal "power transformer".. ie: "Bandwidth at -3 dB must extend from about 0.7 Hz or less to at least 25 kHz for a Bessel function rolloff, or to as high as 70 kHz for other types of rolloff, to assure accurate reproduction in the time domain."
An audio transformer must also have zero DC resistance... blah blah blah.. to save me quoting it all read the article here: http://www.jeffrowland.com/tectalk2.htm
From all this, and from other sources, it can be seen that my power transformer toroidal was not really the best choice as it's frequencies were pretty limited. In fact, that could explain why using the transformer with the x-can produced a much smoother sound.
I may be talking complete BullSh*t here (probably am) but am led to believe there are "audio toroidals and power toroidals" as there are also "audio laminated" and "power Laminated"... also toroidals hate even the smallest amount of DC in the supply (from other household equipment) and tend to buzz when faced with any stray DC.
To cut to the chase as you say in America... I was out in the garage and took an old cassette deck apart only to find its transformer (audio transformer) was 20VA / 12V so wired it up and fed it to the x-can. Completely different sound, the smoothness had disappeared but the high frequencies were back without a hint of the harshness that was evident using the wall wart. This was, by far, a much better and more realistic sound than that of the toroidal.... the toroidal "did" sound smoother but now I come to think of it..... it was probably cause the high frequencies weren't there!
As to the current rating of the toroidal, the technical guy at Musical fidelity reckons he uses a 500 VA transformer to power his "x-ponents.. he said "you can't get big enough when it comes to transformers, as long as the voltage is the same you won't face any difficulties"
I must say though, I certainly wouldn't use a transformer that was the size of a fridge to power the x-can. It may "sound" better but you've got to draw the line.
I called the manufacture of the toroidal this morning and asked him if he would take the transformer back and exchange it for an "audio transformer" I don't think he knew what I meant by "audio" ( I think they specialize in making transformers for fridges and freezers etc) but he told me to keep the toroidal and he would send me a 12V 20VA laminated job. I doubt it will ever go into service if it turns out to be another "power transformer" but at least I'll have 2 for the price of one rusting away in the garage.
That's upgrading though... 9 out of 10 purchases are a complete waste of money and you always run the risk of blowing your equipment to bits into the bargain! To add insult to injury I have also ordered a set of JJ valves and a set of Mullards.. £50 for the 2 sets....... Once they arrive I'll probably be told they are not suitable for "audio" use. If they make the sound any better I will report though.
The guy I ordered them from was ever so helpful and he also confirmed the "audio transformer" was the way to go and he could supply one for £120 blah blah blah...........
Sometimes, too much information can really be a bad thing and you end up going around in circles. Usually when I get to this stage I put a for sale sticker on my equipment but I think I'll try the valves out before being hasty to get rid this time.
As they say... "patience is a virtue" who knows, tomorrow may be all sunshine and roses..... today was dark, gloomy and miserable and I feel like chucking my entire system out the window.
Man, what ever happened to just plugging the *****in stuff into the wall and enjoying the sound? It must be an "age" thing.. when I was younger everything sounded good. Is that a case of "ignorance is bliss" or is it a hard fact that I've turned into a middle aged fart who is trying to (unsuccessfully) recapture that natural sense of aural pleasure that every "young ear" is blessed with?
crap.... that certainly was a bad day! I'm off to drown my misery in a few whiskies (bottles) and will sit listening to some really depressing leonard cohen thinking how "harsh" the high frequencies sound and what a crap world it is and what an ugly looking mother the x-can is and what a crap pair of headphones I have.............................................. ......................
Sorry if that was a strange post but I don't feel too good today.
All the best
Pinkie
| Originally posted by Dreamslacker Hmm... So the filter on the IEC's not good and the toroid you have is no better than a laminated core transformer? I always thought the Toroidals are better. Maybe it's cos I've always seen Lindbergh toroids only.
But I must say the height of toroids make them awfully tempting to use. |
I'm sorry Dreamslacker but I didn't explain what I meant correctly.
I was reading somewhere that to get the best out of any audio equipment it's essential to use an "audio transformer" as these have a much higher bandwidth than a normal "power transformer".. ie: "Bandwidth at -3 dB must extend from about 0.7 Hz or less to at least 25 kHz for a Bessel function rolloff, or to as high as 70 kHz for other types of rolloff, to assure accurate reproduction in the time domain."
An audio transformer must also have zero DC resistance... blah blah blah.. to save me quoting it all read the article here: http://www.jeffrowland.com/tectalk2.htm
From all this, and from other sources, it can be seen that my power transformer toroidal was not really the best choice as it's frequencies were pretty limited. In fact, that could explain why using the transformer with the x-can produced a much smoother sound.
I may be talking complete BullSh*t here (probably am) but am led to believe there are "audio toroidals and power toroidals" as there are also "audio laminated" and "power Laminated"... also toroidals hate even the smallest amount of DC in the supply (from other household equipment) and tend to buzz when faced with any stray DC.
To cut to the chase as you say in America... I was out in the garage and took an old cassette deck apart only to find its transformer (audio transformer) was 20VA / 12V so wired it up and fed it to the x-can. Completely different sound, the smoothness had disappeared but the high frequencies were back without a hint of the harshness that was evident using the wall wart. This was, by far, a much better and more realistic sound than that of the toroidal.... the toroidal "did" sound smoother but now I come to think of it..... it was probably cause the high frequencies weren't there!
As to the current rating of the toroidal, the technical guy at Musical fidelity reckons he uses a 500 VA transformer to power his "x-ponents.. he said "you can't get big enough when it comes to transformers, as long as the voltage is the same you won't face any difficulties"
I must say though, I certainly wouldn't use a transformer that was the size of a fridge to power the x-can. It may "sound" better but you've got to draw the line.
I called the manufacture of the toroidal this morning and asked him if he would take the transformer back and exchange it for an "audio transformer" I don't think he knew what I meant by "audio" ( I think they specialize in making transformers for fridges and freezers etc) but he told me to keep the toroidal and he would send me a 12V 20VA laminated job. I doubt it will ever go into service if it turns out to be another "power transformer" but at least I'll have 2 for the price of one rusting away in the garage.
That's upgrading though... 9 out of 10 purchases are a complete waste of money and you always run the risk of blowing your equipment to bits into the bargain! To add insult to injury I have also ordered a set of JJ valves and a set of Mullards.. £50 for the 2 sets....... Once they arrive I'll probably be told they are not suitable for "audio" use. If they make the sound any better I will report though.
The guy I ordered them from was ever so helpful and he also confirmed the "audio transformer" was the way to go and he could supply one for £120 blah blah blah...........
Sometimes, too much information can really be a bad thing and you end up going around in circles. Usually when I get to this stage I put a for sale sticker on my equipment but I think I'll try the valves out before being hasty to get rid this time.
As they say... "patience is a virtue" who knows, tomorrow may be all sunshine and roses..... today was dark, gloomy and miserable and I feel like chucking my entire system out the window.
Man, what ever happened to just plugging the *****in stuff into the wall and enjoying the sound? It must be an "age" thing.. when I was younger everything sounded good. Is that a case of "ignorance is bliss" or is it a hard fact that I've turned into a middle aged fart who is trying to (unsuccessfully) recapture that natural sense of aural pleasure that every "young ear" is blessed with?
crap.... that certainly was a bad day! I'm off to drown my misery in a few whiskies (bottles) and will sit listening to some really depressing leonard cohen thinking how "harsh" the high frequencies sound and what a crap world it is and what an ugly looking mother the x-can is and what a crap pair of headphones I have.............................................. ......................
Sorry if that was a strange post but I don't feel too good today.
All the best
Pinkie
Dreamslacker
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Quote:
Nice site. But I do believe they meant using 20:1 output transfomers typically used in Tube amps. Not exactly power transformers used in audio equipment. I do suppose if you do find an output transformer with higher enough VA, that's fine.
Quote:
Singapore actually. We just tell each other to stop beating around the bush here.
Quote:
True. But that's where the fun is, yes?
Quote:
Heh.. Maybe it's both. Try taking a ride on the Underground in a full loop. I think it'd be a pleasure to listen to the X-cans after that.
Quote:
Hey! It's alright and that was a great post!!
Just chill and take a long nap....
| Originally posted by PinkFloyd I'm sorry Dreamslacker but I didn't explain what I meant correctly. An audio transformer must also have zero DC resistance... blah blah blah.. to save me quoting it all read the article here: http://www.jeffrowland.com/tectalk2.htm From all this, and from other sources, it can be seen that my power transformer toroidal was not really the best choice as it's frequencies were pretty limited. In fact, that could explain why using the transformer with the x-can produced a much smoother sound. I may be talking complete BullSh*t here (probably am) but am led to believe there are "audio toroidals and power toroidals" as there are also "audio laminated" and "power Laminated"... also toroidals hate even the smallest amount of DC in the supply (from other household equipment) and tend to buzz when faced with any stray DC. |
Nice site. But I do believe they meant using 20:1 output transfomers typically used in Tube amps. Not exactly power transformers used in audio equipment. I do suppose if you do find an output transformer with higher enough VA, that's fine.
Quote:
| Originally posted by PinkFloyd To cut to the chase as you say in America... |
Singapore actually. We just tell each other to stop beating around the bush here.
Quote:
| Originally posted by PinkFloyd That's upgrading though... 9 out of 10 purchases are a complete waste of money and you always run the risk of blowing your equipment to bits into the bargain! |
True. But that's where the fun is, yes?
Quote:
| Originally posted by PinkFloyd Man, what ever happened to just plugging the *****in stuff into the wall and enjoying the sound? It must be an "age" thing.. when I was younger everything sounded good. Is that a case of "ignorance is bliss" or is it a hard fact that I've turned into a middle aged fart who is trying to (unsuccessfully) recapture that natural sense of aural pleasure that every "young ear" is blessed with? |
Heh.. Maybe it's both. Try taking a ride on the Underground in a full loop. I think it'd be a pleasure to listen to the X-cans after that.
Quote:
| Originally posted by PinkFloyd crap.... that certainly was a bad day! I'm off to drown my misery in a few whiskies (bottles) and will sit listening to some really depressing leonard cohen thinking how "harsh" the high frequencies sound and what a crap world it is and what an ugly looking mother the x-can is and what a crap pair of headphones I have.............................................. ...................... Sorry if that was a strange post but I don't feel too good today. All the best Pinkie |
Hey! It's alright and that was a great post!!
Just chill and take a long nap....
PinkFloyd
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PSU Mark 11 is completed and it has made a subtle change over the toroidal but I can't really say if it's due entirely to the PSU as I changed the valves (tubes) to JJ E88CC's yesterday.
They are still burning in and I haven't really heard them at their best yet but one thing is for CERTAIN..... I substituted the wallwart for the homemade PSU and there was an "immediate" improvement to the sound which suggests the wallwart is seriously underpowered for the job.
The X-Can heated up instead of the power supply which is the way it "should" be! the only reason a transformer gets hot is if it's being asked to deliver more current than it can supply... the wallwart is probably deliberately under rated in current just to get the customer to fork out an additional £200 on the power supply.
"Of Course" the sound is much improved as the amp is being fed the diet is has been designed to receive! with the wallwart the amp is being "rationed" with a very small diet of current and never really "sings" to its full potential as a result.
This has been a steep learning curve but after a lot of research, and the advice of a valve amp manufacturer, I have settled on the 20VA / 12V values as they seem to suit the amps requirements perfectly. Sure you can use a 1000VA / 12V transformer but the higher price of the transformer wouldn't necessarily give you any greater performance levels.
The issue here is not one of "will too much current damage the amp?" It's all about supplying the amp with the current it needs. the 500ma wallwart doesn't have enough current to allow the x-cans circuitry to perform optimally so it is more likely to damage the amp due to melting down under load.
The analogy I was given by the valve amp manufacturer was as follows:
You are hungry and you need 1000 calories to perform at your best...
Wallwart = you are given one potato equaling 500 calories. The potato is not enough to see you reach peak potential but it's enough to get you going.
20VA Power supply = You are given 20 potatoes but you will only eat what you need to satisfy your hunger... just because there are 20 potatoes doesn't mean you will eat them all.
Same with current... the amp will only eat what it requires, it will not demand to eat every ampere that's available.
The X-Can V2 could draw its current from a 1,000,000,000 VA transformer without any problems. The only real issue is making sure the voltage is 12 volts...... if the voltage is higher or lower then you could have problems. (anywhere between 12v - 13v is within limits)
I am now in a position to absolutely recommend a DIY alternative to the wallwart but be sure the voltage of the transformer you use is between 12v -13v... if in doubt always consult somebody with some test equipment.
You can see the latest revision here: http://freespace.virgin.net/rock.grotto/index2.htm and click on the "power supply design" link. Please give the page time to fully load as it has quite a lot of pictures on it. The modifications are near the bottom of the page but it's worthwhile reading the entire page.
A more exotic design is in the pipeline featuring cast iron tube with built in PSU encased in resin with aluminium fascia and backplate...... will upload details as soon as.
Pinkie
They are still burning in and I haven't really heard them at their best yet but one thing is for CERTAIN..... I substituted the wallwart for the homemade PSU and there was an "immediate" improvement to the sound which suggests the wallwart is seriously underpowered for the job.
The X-Can heated up instead of the power supply which is the way it "should" be! the only reason a transformer gets hot is if it's being asked to deliver more current than it can supply... the wallwart is probably deliberately under rated in current just to get the customer to fork out an additional £200 on the power supply.
"Of Course" the sound is much improved as the amp is being fed the diet is has been designed to receive! with the wallwart the amp is being "rationed" with a very small diet of current and never really "sings" to its full potential as a result.
This has been a steep learning curve but after a lot of research, and the advice of a valve amp manufacturer, I have settled on the 20VA / 12V values as they seem to suit the amps requirements perfectly. Sure you can use a 1000VA / 12V transformer but the higher price of the transformer wouldn't necessarily give you any greater performance levels.
The issue here is not one of "will too much current damage the amp?" It's all about supplying the amp with the current it needs. the 500ma wallwart doesn't have enough current to allow the x-cans circuitry to perform optimally so it is more likely to damage the amp due to melting down under load.
The analogy I was given by the valve amp manufacturer was as follows:
You are hungry and you need 1000 calories to perform at your best...
Wallwart = you are given one potato equaling 500 calories. The potato is not enough to see you reach peak potential but it's enough to get you going.
20VA Power supply = You are given 20 potatoes but you will only eat what you need to satisfy your hunger... just because there are 20 potatoes doesn't mean you will eat them all.
Same with current... the amp will only eat what it requires, it will not demand to eat every ampere that's available.
The X-Can V2 could draw its current from a 1,000,000,000 VA transformer without any problems. The only real issue is making sure the voltage is 12 volts...... if the voltage is higher or lower then you could have problems. (anywhere between 12v - 13v is within limits)
I am now in a position to absolutely recommend a DIY alternative to the wallwart but be sure the voltage of the transformer you use is between 12v -13v... if in doubt always consult somebody with some test equipment.
You can see the latest revision here: http://freespace.virgin.net/rock.grotto/index2.htm and click on the "power supply design" link. Please give the page time to fully load as it has quite a lot of pictures on it. The modifications are near the bottom of the page but it's worthwhile reading the entire page.
A more exotic design is in the pipeline featuring cast iron tube with built in PSU encased in resin with aluminium fascia and backplate...... will upload details as soon as.
Pinkie
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