Yes, good or bad is purely subjective, experience based.
That doesn't mean it's perfect or better. It's still being split but this time in a way that you don't or can't control as you do with the amplifier unless you undo the CD player and test it like your amps.
I prefer a SE amp if I don't want a splitter. With the right speakers it's unbeatable. 🙂
Inside many recording studios, and post production studios, there are all sorts of balanced signals, microphones, boards, etc.
None of them are perfect.
But, we all accept them if the studio made our favorite recording.
We can not, and do not control the studio, post production house, etc.
The point of my balanced vacuum tube amplifier is that it is essentially push pull all the way through, but without any vacuum tube phase splitter.
(perhaps the studio or the post production house used a vacuum tube splitter, if only to run the monitor loudspeakers).
Just try and tell some of the solid state fans that their beloved circuit that has a phase splitter is no good.
And some of those studios and post production houses use solid state 2 phase outputs, etc.
Phase splitting Abounds.
Whatever phase splitting was, or was not used, to make a recording . . . you can not control that when you use a CD player to drive a vacuum tube single ended amplifier.
And I Do like single ended tube amplifiers.
Tradeoffs, Tradeoffs, Tradeoffs.
Systems, Systems, Systems
None of them are perfect.
But, we all accept them if the studio made our favorite recording.
We can not, and do not control the studio, post production house, etc.
The point of my balanced vacuum tube amplifier is that it is essentially push pull all the way through, but without any vacuum tube phase splitter.
(perhaps the studio or the post production house used a vacuum tube splitter, if only to run the monitor loudspeakers).
Just try and tell some of the solid state fans that their beloved circuit that has a phase splitter is no good.
And some of those studios and post production houses use solid state 2 phase outputs, etc.
Phase splitting Abounds.
Whatever phase splitting was, or was not used, to make a recording . . . you can not control that when you use a CD player to drive a vacuum tube single ended amplifier.
And I Do like single ended tube amplifiers.
Tradeoffs, Tradeoffs, Tradeoffs.
Systems, Systems, Systems
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@6A3sUMMER, good for you that you investigated all this stuff. I have never wasted one minute in investigating CD recording deeper than basic stuff because my reference is still the vinyl record (with SE amp and dedicated speakers). Old vinyl recording had/has limits of course, some of these make it look much worse than CD but reality is different. It still sounds best to me no matter what (assuming one has a good deck). That's unquestionable.
So for me, whatever phase splitter is more convenient for the actual task (sounds best) that is my choice. There is no pre-definite choice and there is no best splitter. Going to tell people that they have a phase splitter that is no good is pretty pointless. It is what is. It's not my system.
So for me, whatever phase splitter is more convenient for the actual task (sounds best) that is my choice. There is no pre-definite choice and there is no best splitter. Going to tell people that they have a phase splitter that is no good is pretty pointless. It is what is. It's not my system.
45,
Good points!
I am not currently set up to play my Vinyl collection.
I love Vinyl!
Once I am set up again, I will use my CCS cathode coupled phase splitter amplifiers, rather than build a phono preamp with XLR outputs, etc.
Good points!
I am not currently set up to play my Vinyl collection.
I love Vinyl!
Once I am set up again, I will use my CCS cathode coupled phase splitter amplifiers, rather than build a phono preamp with XLR outputs, etc.
Butting in…in my experience, the quality of the music + the quality of the recording trump the media.
I have heard great things on CD, vinyl and even tape and digital files. They all had 1 thing in common great music + great recording.
Even further, I have a number of Three Blind Mice records that were transferred to CD, and they sound amazing too. So, it seems greatness transfers from media to media too.
Finally, I am glad everyone has the option to enjoy a format that suits them best!
I have heard great things on CD, vinyl and even tape and digital files. They all had 1 thing in common great music + great recording.
Even further, I have a number of Three Blind Mice records that were transferred to CD, and they sound amazing too. So, it seems greatness transfers from media to media too.
Finally, I am glad everyone has the option to enjoy a format that suits them best!
One of the more popular microphone preamps is the Ampex 351 in recording studios and it uses a paraphase phase inverter to drive its PP output stage. I know because I restored several of those. Almost all studios have compressors and if they don't use LA2A optical compressor then another tube unit would have to be a vari-mu compressor such as Altec 436 or RCA BA6A or UA 175, etc... which by nature is almost always PP all the way through to cancel its distortion caused by variable DC condition. Almost all vintage recording gears are bracketed by input and output transformers whether they're SE or PP operation.
I am planning to build an individual PP driver stage with use of the Monolith ITA-02 20mA 1+1 : 1+1 interstage transformer. The driver tube could be ECC88/6DJ8 differential with CCS at common cathode. This would provide very clean signal to drive either SE or PP power stage.
The Monolith ITA-02 20mA 1+1 : 1+1 (but also the other Monoliths of that series) are either SE to SE or PP to PP. According to the manufacturer, PP to SE or SE to PP will heavily upset the high frequency response of the transformer because of poor distribution of capacitances for such applications. So, if used to drive a SE output stage the driver has to be SE. Try and see. There might be an insulation issue as well. If I remember correctly the 02 is bifilar.
Wonderful article here by Thorsten Loesch sheds an awful lot of light on the subject of anyone else finds themselves in the same position.
https://community.fortunecity.ws/rivendell/xentar/1179/theory/seamptheory/SEAmplifiertheory.html
https://community.fortunecity.ws/rivendell/xentar/1179/theory/seamptheory/SEAmplifiertheory.html
Thorsten Loesch . . .
One very interesting circuit in that link was the Medium Mu Triode Cascade:
Dual drivers, one for each 300B. Issues: balance of the two independent drivers.
Parallel 300B tubes in single ended (PSE), each with its own individual self bias network.
Thanks stretchneck!
One very interesting circuit in that link was the Medium Mu Triode Cascade:
Dual drivers, one for each 300B. Issues: balance of the two independent drivers.
Parallel 300B tubes in single ended (PSE), each with its own individual self bias network.
Thanks stretchneck!
Great article, thanks for the link!
In the Meduim Mu Triode Cascade, a PSE driver and a PSE output stage, the 5687 will probably dominate the distortion profile. This was my experience in the simple Amity amplifier, with a 5687 input/driver. The 5687, 7044, and 7119 dominated the sound of the amplifier. A triode-connected 6V6 would probably be a better choice, while retaining the one-driver-per-300B approach of the original article.
In the Meduim Mu Triode Cascade, a PSE driver and a PSE output stage, the 5687 will probably dominate the distortion profile. This was my experience in the simple Amity amplifier, with a 5687 input/driver. The 5687, 7044, and 7119 dominated the sound of the amplifier. A triode-connected 6V6 would probably be a better choice, while retaining the one-driver-per-300B approach of the original article.
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Well said 45. Phase splitting in transformers is not a recipie for good sound. So we can ignore those multi tapped universal It. They dont work. Another variable to the mix is SE modulates the power supply much more ripple impossed than PP.
Well, @Michael C, let me say phase splitting at interstage level is not the best option except some cases where the reuirements are mild. So it's not a good option for 300B but can be a good choice for other applications.
At the input it's a whole different story, in particular if one uses top-notch transformers. My favourites are the Sowter 1475 and 9063, depending on which input impedance I want (high or standard 600R). They do exactly what they claim. Brilliant stuff!
https://www.sowter.co.uk/specs/1475.php
https://www.sowter.co.uk/specs/9063.php
At the input it's a whole different story, in particular if one uses top-notch transformers. My favourites are the Sowter 1475 and 9063, depending on which input impedance I want (high or standard 600R). They do exactly what they claim. Brilliant stuff!
https://www.sowter.co.uk/specs/1475.php
https://www.sowter.co.uk/specs/9063.php
Agree. There are superb studio-quality input phase splitters. Those are the ones to use.
If both balanced and single-ended sources are available, it is simple to switch-bypass the secondary of the input transformer when balanced sources are used, and go straight into the paired input grids (with grid resistors between 47 and 100 K per grid).
Similarly, there are quite good balanced interstage transformers to go between the PP driver pair and the PP output pair. Much easier to design the IT if the source is reasonably low impedance (2 K or less Rp per tube) and symmetric.
For example, the 45 DHT, triode-connected 6V6, and 5687/7044/7119 are all less than 2 K Rp, and each plate can linearly swing +/- 85 volts or more. That will drive any 300B into full clipping.
If both balanced and single-ended sources are available, it is simple to switch-bypass the secondary of the input transformer when balanced sources are used, and go straight into the paired input grids (with grid resistors between 47 and 100 K per grid).
Similarly, there are quite good balanced interstage transformers to go between the PP driver pair and the PP output pair. Much easier to design the IT if the source is reasonably low impedance (2 K or less Rp per tube) and symmetric.
For example, the 45 DHT, triode-connected 6V6, and 5687/7044/7119 are all less than 2 K Rp, and each plate can linearly swing +/- 85 volts or more. That will drive any 300B into full clipping.
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They are hard to get right and have to be specifically designed for phase splitting purposes. You can't take a random interstage transformer and expect to behave well in splitting phase mode. I made a perfectly balanced SE😛P phase splitter interstage over the whole frequency spectrum, but it took me 3 years of figuring it out, +50 sketch sheets ands 5-6 prototypes. Lekage inductance and all capacitances have to be balanced over the geometry and the tiniest shift will affect one half of the signal than the other. In my latest trial, I used a double bobbin C-core with balanced screens to equalize even the tiniest capacitance differences.
Echoing 50AE, interstage transformers are the hardest of all transformers to design, which is why they are not common, and good ones are pretty rare. Adding in an additional requirement for SE -> PP conversion just makes it that much harder.
Indeed, it is impossible to wind a perfectly symmetrical center-tapped winding. But a transformer, input or interstage, can be an ideal phase splitter if there is a single secondary winding whose ends, connected to PP grids, produce opposite phases.
