This is true! Though you can use a pentode/triode cascode. Actually, nobody ever specifically ruled out the zener stack. I believe the later sentiment was that sand should "not be on the plate". So if this is the case, zeners references might be allowed.
In any case, the old-school LW method is indeed simpler. Also, it performs nicely too. You can also use a plate choke in the 'monkey' method. These are the main topologies discussed so far.
Yes, he has that in a schematic as well as discussing LC in the text somewhere I remember.
I have had very nice results using LC and LCLC power supplies, so tend to favour them.
Well, perhaps. I too have a tek scope... and a pair of S9, also a circuit to build and I guess we shall see (choke loaded and direct coupled as not wander too far from the OP).
It would strike me as somewhat odd if the manufacturer and the winder both arrived at similar measurements by collusion, and all which that implies.
Thanks for your time.
Hanze.
If you (as the OP) are open to pursuing this, I can ask the designer at Whammadyne (via Linked-in) and report back..
Let me know.
Hanze
TM515
Hi Hanze
The TM515 is just a frame
The cards needed are the oscillator and anaylizer
This is not a forum for business or producers to argue they're case
Each DIYer needs to build and measure their own gear
Manufactures can measure their products in many different ways
When you build your DIY project it would be great for you to post the results while the OPTs are in an active amplifier
Maybe at 1 watt and full power with a full spectrum set of plots
Amplitude and freq response with distortion
And what test gear was used
I wish you well with this project so as to inspire others to excellence
Many who read these forums need basic info in a form they can digest
I= V/R and a voltmeter and scope from eBay is their start
Hi Hanze
The TM515 is just a frame
The cards needed are the oscillator and anaylizer
This is not a forum for business or producers to argue they're case
Each DIYer needs to build and measure their own gear
Manufactures can measure their products in many different ways
When you build your DIY project it would be great for you to post the results while the OPTs are in an active amplifier
Maybe at 1 watt and full power with a full spectrum set of plots
Amplitude and freq response with distortion
And what test gear was used
I wish you well with this project so as to inspire others to excellence
Many who read these forums need basic info in a form they can digest
I= V/R and a voltmeter and scope from eBay is their start
Attachments
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Perfectusaudio said:
The Truth seems hard to believe !Hanze
Well, you cannot make these statements without proof, and certainly not without offering the right of reply. Especially so if you may (or may not) offer a similar product for retail sale. I object to your comment regarding those who do not yet understand Ohms Law. As to this condescension, I would say that it is matched only by the arrogance that your moniker presents with.
Please read below - and yes this is for a DC coupled amplifier with choke loaded driver, just so we don't get too upset.
--
Hello, I appreciate your question in regards to BW of our Truth amplifier. The fact of the matter is yes it does extend to 140 Khz and is documented as such in our measurements and as specified in our performance published specifications. Our lab tests are real and accurate. We used several test methods to determine this bandwidth. Several including one of our instruments for this measurement an HP Spectrum analyzer model 3585A actually two machines, both our lab and my associate engineers lab have the same models and independently confirmed each others test results. I would just say in closing the (many) that might suggest it cannot be done have not done the actual tests. I would also defer you to correspond with Dr. Ward of Monolith Magnetics Sincerely, Pat Whammerdyne Heavy Industries
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Dear Hanze.
1. This is a DIY board.
2. Everyone has an opinion.
3. People who last long here make a big effort to respect other's opinions, even when they fully believe those opinions to be flawed.
I might suggest that very few people on this board are likely to have much interest in purchasing such an expensive finished product as from the company that you might be promoting.
Believe me. Do a search of the forum, and you will likely find that many of us get excited about cheap stuff that nobody loves.
Just my 2cents, but a slick website puts me off almost immediately. Most people I know who have a PhD or DPhil don't use Dr. in their name unless they happen also to be a physician, dentist, etc.
1. This is a DIY board.
2. Everyone has an opinion.
3. People who last long here make a big effort to respect other's opinions, even when they fully believe those opinions to be flawed.
I might suggest that very few people on this board are likely to have much interest in purchasing such an expensive finished product as from the company that you might be promoting.
Believe me. Do a search of the forum, and you will likely find that many of us get excited about cheap stuff that nobody loves.
Just my 2cents, but a slick website puts me off almost immediately. Most people I know who have a PhD or DPhil don't use Dr. in their name unless they happen also to be a physician, dentist, etc.
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Dear 'dealer of souls', and with regard to your points 1,2 and 3.
1. yep
2. Opinions without foundation, un-tested, should not be put forth as 'fact' - 'I find this unbelievable' - then so be it and then prove it so, or swallow your pride. And without items at hand, it is for you impossible. Yet we have the testimony of the manufacturer of a highly regarded amplifier, confirming such. Question becomes - why would you not believe it, why forth the slander - do you have a commercial interest?
3. Irrelevant. We are talking (if you would accommodate) about reality.
I am not promoting anything, just attempting to bring lies (slander, and there are legal ramifications associated with this) to light. I do not sell, nor have I sold, or have any intention to sell OPT's.
My interest is held purely in the interest of facts and as they relate to the OP about DC coupled SE designs, by nature involving an OPT and the best results are of course paramount to this discussion.
There are OPT which can accommodate HF out to ~140kHz, I do not produce them, but they are available. Seems to me, if you want a mediocre OPT you would not be short on options.
Again, all to do with DC coupled amplifiers with choke loaded drivers.
To argue with me will be fruitless to you.
Hanze
1. yep
2. Opinions without foundation, un-tested, should not be put forth as 'fact' - 'I find this unbelievable' - then so be it and then prove it so, or swallow your pride. And without items at hand, it is for you impossible. Yet we have the testimony of the manufacturer of a highly regarded amplifier, confirming such. Question becomes - why would you not believe it, why forth the slander - do you have a commercial interest?
3. Irrelevant. We are talking (if you would accommodate) about reality.
I am not promoting anything, just attempting to bring lies (slander, and there are legal ramifications associated with this) to light. I do not sell, nor have I sold, or have any intention to sell OPT's.
My interest is held purely in the interest of facts and as they relate to the OP about DC coupled SE designs, by nature involving an OPT and the best results are of course paramount to this discussion.
There are OPT which can accommodate HF out to ~140kHz, I do not produce them, but they are available. Seems to me, if you want a mediocre OPT you would not be short on options.
Again, all to do with DC coupled amplifiers with choke loaded drivers.
To argue with me will be fruitless to you.
Hanze
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None. What I do in my day job compensates me far better than any commercial venture in audio ever could. There are threads here on this topic and what a tough go it is.
Then feel free to mention these OPT's, the manufacturing processes they employ, etc. with real measured data, plots, details of measurements, etc. Believe it or not, there are many people who wind their own transformers on this board and they can share quite a bit of experience.
Sometimes a newer producer comes out with OPT's but zero data. They rely on word of mouth, etc. Maybe they build a flashy website. All fine, but such impressive claims still should come with impressive evidence in my book.
Those tango XE20s on my single ended 2a3 amplifier are quite fine and I bought them at an extremely attractive price. The owner wanted to get rid of them since they were 'faulty'. I only needed to properly de-gauss them.
Also, don't forget the transducer or the source. I do some of my own measurements using a microphone, external soundcard, freeware and a laptop. Quite decent professional spectrum analyzers of yesteryear can often now be picked up for a fraction of their original price too I hear.
Anyway, no disrespect is intended from my posts. And yes by all means, help yourself to some Soul...
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Hi Perfectaudio
I also have a pair of FC-12s. I found they were ok with 45 tubes. I could make them work for 46's as long as the speakers were 6 ohms impedance or more.
The only small problem I had with them was the bass. Look at the iso specs sheets and you will see that it drops 5db at 20 Hz and 10db at 10 Hz if you are using the 7k primaries... I knew this in advance of course so my expectations were not set too high to start with.
I see that the new ISO company is selling new FC-20S for ¥25,500 apiece. This is about $240 at current exchange rates (excluding shipping).
At this price, I would consider buying a pair the next time I am in Tokyo on business, but to be honest I already have too many projects on the go. Maybe it would be worth looking for used ones, since they should easily come under this price in Japan at least.
There is no way I could wind and pot an OPT of this quality for this price myself... Or maybe it is possible? What is your thought on this?
I also have a pair of FC-12s. I found they were ok with 45 tubes. I could make them work for 46's as long as the speakers were 6 ohms impedance or more.
The only small problem I had with them was the bass. Look at the iso specs sheets and you will see that it drops 5db at 20 Hz and 10db at 10 Hz if you are using the 7k primaries... I knew this in advance of course so my expectations were not set too high to start with.
I see that the new ISO company is selling new FC-20S for ¥25,500 apiece. This is about $240 at current exchange rates (excluding shipping).
At this price, I would consider buying a pair the next time I am in Tokyo on business, but to be honest I already have too many projects on the go. Maybe it would be worth looking for used ones, since they should easily come under this price in Japan at least.
There is no way I could wind and pot an OPT of this quality for this price myself... Or maybe it is possible? What is your thought on this?
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Read what you wrote, and tell me again.
Semantics aside, if the winder claims >150kHz bandwidth, and a manufacturer of a well received commercial product at five figures confirms the same as the overall BW of the amplifier, one might take this at face value. And, when questioned the manufacturer backs the specification and then provides all relevant detail to support the measurements.
All of which flies directly into the face of your words 'such crap', and '-30dB at 100kHz' (please feel free in correcting me if I am quoting out of context) and illuminates your commentary for what it is.
I think its safe to say that you've conveniently skipped the issue - that being your comments 'it seems the Truth is hard to believe', and also 'such crap'. With the hard facts now in-front of you it seems you resort to some sappy retraction, which I suspect would be very unbecoming, even in the world of Pefectusaudio.
It might be time to admit that you know nothing of Monolith Magnetics, their OPT, or commercial products in which they are employed, and your dinosaur age preconceived notions are just exactly that.
Hanze
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Is it Monolith Magnetics? They have a good reputation. I know they can do custom wind jobs too. At first glance their export prices don't look terrible. Of course they have a reputation for BIG transformers, and shipping alone might make a purchase un-economical for some buyers.
Their PSU chokes are tempting, but am pretty happy with Lundahl. Their plate chokes look a bit pricey too.
However, their interstage transformers are kind of interesting to me. The IT-01 and IT-03/25 have some impressive specs...
Haze - have you used these interstages before? Are they potted? To be honest, I prefer non-potted if it can be had cheaper. Ever compared them to Lundahl?
Of course this gets totally off topic... sorry for this question.
Their PSU chokes are tempting, but am pretty happy with Lundahl. Their plate chokes look a bit pricey too.
However, their interstage transformers are kind of interesting to me. The IT-01 and IT-03/25 have some impressive specs...
Haze - have you used these interstages before? Are they potted? To be honest, I prefer non-potted if it can be had cheaper. Ever compared them to Lundahl?
Of course this gets totally off topic... sorry for this question.
Hi Soulmerchant ,
I think we all have to make up our own minds as to the metal we use on any given project.
Edcor I see are promoting a new line of transformers of M6 laminations 20Hz to 20Khz -1db if my memory serves me correctly which will cover most needs of the DIY community considering we can't hear much above 20Khz as an infant and much less as an adult.
The harmonics that reach back to 20Khz of the most prominent instrument the cymbals at 100kHz is about 2% if I am reading the research correctly ,most other instruments fall below 0.5% so we know what difference in freq response we can hear is approx 1dB so my real point to all this is what happens to the waveform and performance of core material within the 20-20Khz we can hear .
M19 and M6 -M3 metal IMHO do the best job of this at 20-20kHz .
It is I believe very important to build you amp as you have done and discover what suits your needs.
I also believe the bulk of DIYers are not intent on spending large sums of money on OPTs
so bang for the buck seems very important .
As for used OPTs eBay is full of them they don't wear out .
I think we all have to make up our own minds as to the metal we use on any given project.
Edcor I see are promoting a new line of transformers of M6 laminations 20Hz to 20Khz -1db if my memory serves me correctly which will cover most needs of the DIY community considering we can't hear much above 20Khz as an infant and much less as an adult.
The harmonics that reach back to 20Khz of the most prominent instrument the cymbals at 100kHz is about 2% if I am reading the research correctly ,most other instruments fall below 0.5% so we know what difference in freq response we can hear is approx 1dB so my real point to all this is what happens to the waveform and performance of core material within the 20-20Khz we can hear .
M19 and M6 -M3 metal IMHO do the best job of this at 20-20kHz .
It is I believe very important to build you amp as you have done and discover what suits your needs.
I also believe the bulk of DIYers are not intent on spending large sums of money on OPTs
so bang for the buck seems very important .
As for used OPTs eBay is full of them they don't wear out .
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