What's the best OPT you've come across for 2a3s in PP?
1) Where in the range of 3K - 6.6K primaries?
2) Which make?
My experience is that O-netics 6.6K is really good - that's my main listening amp - but I'm looking at a second amp and what's available internationally - Silk, James, Lundahl, AE, US makes and other exotics.
Also interested in good value choices. One is the Danbury 6.6K one Maplins used to sell in the UK. Surprisingly good and very cheap. another is Hammond 5K 1615A, never heard that but right kind of specs.
So generally looking around for opinions! I'm using 2a3 PP amps now instead of 300b SETs. Prefer the sound after several comparisons.
andy
1) Where in the range of 3K - 6.6K primaries?
2) Which make?
My experience is that O-netics 6.6K is really good - that's my main listening amp - but I'm looking at a second amp and what's available internationally - Silk, James, Lundahl, AE, US makes and other exotics.
Also interested in good value choices. One is the Danbury 6.6K one Maplins used to sell in the UK. Surprisingly good and very cheap. another is Hammond 5K 1615A, never heard that but right kind of specs.
So generally looking around for opinions! I'm using 2a3 PP amps now instead of 300b SETs. Prefer the sound after several comparisons.
andy
Here's a couple of references:
Hashimoto HW-15-5 5K PP $478 pair
Results for Transformers:Output - Push Pull
Silk P-50-15A 5K PP $375 pair SACThailand
Andy
Hashimoto HW-15-5 5K PP $478 pair
Results for Transformers:Output - Push Pull
Silk P-50-15A 5K PP $375 pair SACThailand
Andy
also:
Tamura F-483 5K PP 15W, 4*,8*,16*
Tango FE-25-5 25W 5K 4,8,16 160mA 83x78x81 1.6Kg
ASV looks interesting! I've been to Slovenia - lovely place, and people there very educated and musical.
Andy
Tamura F-483 5K PP 15W, 4*,8*,16*
Tango FE-25-5 25W 5K 4,8,16 160mA 83x78x81 1.6Kg
ASV looks interesting! I've been to Slovenia - lovely place, and people there very educated and musical.
Andy
I have heard several PP 2A3 amps using vintage Chicago OPTs that came from Eico monoblocks. The Eico HF-20, -22 and -35 all used the same OPT which is 6.6K as I recall. The HF-50 and -60 used different transformers. I have several of these OPTs that I plan eventually on using for PP 2A3 amps, but haven't gotten around to it yet.
Hi Salectric!
I'm getting great results from 26 into 4P1L interstage coupled to 2a3PP. I like the old Chinese biplates - nice and mellow. I find the Sovteks hard sounding. Got some 6C4C as well - should sound nice. I'm using Lundahl LL1660PP interstage, and Hammond 124b plate chokes on the 26 pairs, direct coupled to 4P1Ls. The 124b are half nickel stepdown transformers so I just use one side with the CT as a plate choke - lovely sound. I've been blown away by the detail and musical sound. Better than my 300b SET amps.
It's worth using some nice iron - interstages and plate chokes. Makes a big difference!
Andy
I'm getting great results from 26 into 4P1L interstage coupled to 2a3PP. I like the old Chinese biplates - nice and mellow. I find the Sovteks hard sounding. Got some 6C4C as well - should sound nice. I'm using Lundahl LL1660PP interstage, and Hammond 124b plate chokes on the 26 pairs, direct coupled to 4P1Ls. The 124b are half nickel stepdown transformers so I just use one side with the CT as a plate choke - lovely sound. I've been blown away by the detail and musical sound. Better than my 300b SET amps.
It's worth using some nice iron - interstages and plate chokes. Makes a big difference!
Andy
Hi Andy,
Another opt to look at is the S240A from Magnequest. It's 5k & 20W. $225each in M6, $500 per for nickel. I'm using them in a parafeed 2A3 PP amp and like them very much.
Regards,
John
Another opt to look at is the S240A from Magnequest. It's 5k & 20W. $225each in M6, $500 per for nickel. I'm using them in a parafeed 2A3 PP amp and like them very much.
Regards,
John
Hi Andy,
I used the Hammond 1615 in my first pp 2a3 amp, to see if I liked the idea and sound of 2a3 in pp. The amp itself was based on a design posted here by F.DeGrove, using a paraphase inverter. I did, in fact like the sound, and the amp evolved into a "amity" styled amp (all transformer coupled). I am now using lundahl 1623am outputs. I am not going to bash the hammonds, they give good sound and value for the money, however comparing them to the boutique brands mentioned, they will fall short, particularly in nuance and frequency extremes.
I used the Hammond 1615 in my first pp 2a3 amp, to see if I liked the idea and sound of 2a3 in pp. The amp itself was based on a design posted here by F.DeGrove, using a paraphase inverter. I did, in fact like the sound, and the amp evolved into a "amity" styled amp (all transformer coupled). I am now using lundahl 1623am outputs. I am not going to bash the hammonds, they give good sound and value for the money, however comparing them to the boutique brands mentioned, they will fall short, particularly in nuance and frequency extremes.
Hi Jim,
That's useful to know. So the 1615 is "good but outdone by better makes". I assume all the usual suspects, Hashimoto, Tango, Tamura, O-netics, Silk etc.
andy
That's useful to know. So the 1615 is "good but outdone by better makes". I assume all the usual suspects, Hashimoto, Tango, Tamura, O-netics, Silk etc.
andy
JimW, Do you have a link to the Frank DeGrove design you mentioned? I am interested in trying a paraphase inverter and that may give me some ideas.
Hi Andy,
You may ask to my friend Charly to wind this one for you.
"charlydoria at free dot fr"
Feedback highly welcome.
Yves.
You may ask to my friend Charly to wind this one for you.
"charlydoria at free dot fr"
Feedback highly welcome.
Yves.
Hi Salectric,
I think you could do a search of this forum for pp 2a3 and find it. I am not sure what the exact title of the thread was, I saw the schematic, printed it, and built it a year or so later. Lot of threads floating around re paraphase, can be made to work pretty well by adjusting resistor values in the voltage divider to get ac balance.
Andy,
Yes, I thought the hammond offered acceptable performance, but is bettered by the other manufacturers mentioned. We always recommend boutique grade parts in these threads, don't we. If you have no basis of comparison, the hammond sounds pretty good, and to squeeze the extra performance, the wallet has to be opened widely! As an aside, my pp2a3 began life as a pp 300b, but I could never get it quiet enough (2-2.5 mv), and I didn't really need much power, so I converted it to 2a3.
I think you could do a search of this forum for pp 2a3 and find it. I am not sure what the exact title of the thread was, I saw the schematic, printed it, and built it a year or so later. Lot of threads floating around re paraphase, can be made to work pretty well by adjusting resistor values in the voltage divider to get ac balance.
Andy,
Yes, I thought the hammond offered acceptable performance, but is bettered by the other manufacturers mentioned. We always recommend boutique grade parts in these threads, don't we. If you have no basis of comparison, the hammond sounds pretty good, and to squeeze the extra performance, the wallet has to be opened widely! As an aside, my pp2a3 began life as a pp 300b, but I could never get it quiet enough (2-2.5 mv), and I didn't really need much power, so I converted it to 2a3.
Andy
Which level O'Netics OPT'S do you have ?
Please read this Quote from Budp...
"jrenkin,
Yes these are O-Netics transformers, but the ones found at C3 Amps and Rhodes are only for guitar amps. Anyone can PM me, I will shift you over to my private email when you do, but a PM is always welcome.
As for differences..... hmmm.... Our level one OPT's are likely to be 3 to 4 times the amount of retained signal information, over anything you have heard. Their FR and phase are flat from 20 to 40kHz for both PP and SE at any power level, including up to hard saturation at 20Hz. They will not oscillate and their impedance curve down in the sub sonic realm is very flat, while phase and frequency response roll off very smoothly. Compared to say, a Lundahl 1620, they have slightly but noticeably more distortion, are not as dynamic in transient response, are roughly as clear in tonality and timbre but will have more internal information to note and transient structures. Of the two, I like the 1620 slightly more.
When O-Netics level 3 is in the picture, the low level coherent signals are completely retained, so hall resonances, deeply buried musical signals etc are made clearly apparent. They have another 2 times the information content of level one and provide a complete ease to all sounds, regardless of their complexity or amplitude. Compared again to a 1620 they are slightly softer in presentation, just as clear tonally and transiently, are as vivid, but do leave the Lundahls sounding faintly cartoon like when it comes to deeply complex music, such as Cantate Domino on XRCD or a 24/192 rendering of Carmina Burana, from a live stage production. I wont go into tape or LP's here, but you can expect the same differences with those sources.
These comparisons come from Gary Pimm's system, using his second generation Tabor SS amp, with plug and play interstage and output transformer connections. None of this should be taken as faulting the Lundahl 1620, these are fabulous output transformers, Lundahl and I have just taken two different paths and thus offer different strengths.
Please note that these are very small differences and are really only available from speakers that can exceed the typical downward dynamic limit pointed to by Meyer Sound, of about 40 db below average signal levels, typical with modern dynamic speakers. Ribbon based systems and CD / LeCleach horn systems will provide greater downward dynamic range, as will any EnABL'd dynamic speaker system.
My previous statement about purchasing less revealing transformers still stands. Unless you really do have a very revealing speaker system (and of course we all are certain we do!) there is no real reason to spend from $150 to $600 per output transformer. Even if an exquisite level of signal retention and expression into your listening room is your eventual intention, I would still suggest you utilize under $100 apiece OPT's for all of your development and system proofing work, including hum and noise reduction. Then, spend your money on high resolution speakers, output transformers, speaker cables and signal sources, in that order.
Bud"
This is from the choosing a opt thread, #63 or #67...
dennis h
Which level O'Netics OPT'S do you have ?
Please read this Quote from Budp...
"jrenkin,
Yes these are O-Netics transformers, but the ones found at C3 Amps and Rhodes are only for guitar amps. Anyone can PM me, I will shift you over to my private email when you do, but a PM is always welcome.
As for differences..... hmmm.... Our level one OPT's are likely to be 3 to 4 times the amount of retained signal information, over anything you have heard. Their FR and phase are flat from 20 to 40kHz for both PP and SE at any power level, including up to hard saturation at 20Hz. They will not oscillate and their impedance curve down in the sub sonic realm is very flat, while phase and frequency response roll off very smoothly. Compared to say, a Lundahl 1620, they have slightly but noticeably more distortion, are not as dynamic in transient response, are roughly as clear in tonality and timbre but will have more internal information to note and transient structures. Of the two, I like the 1620 slightly more.
When O-Netics level 3 is in the picture, the low level coherent signals are completely retained, so hall resonances, deeply buried musical signals etc are made clearly apparent. They have another 2 times the information content of level one and provide a complete ease to all sounds, regardless of their complexity or amplitude. Compared again to a 1620 they are slightly softer in presentation, just as clear tonally and transiently, are as vivid, but do leave the Lundahls sounding faintly cartoon like when it comes to deeply complex music, such as Cantate Domino on XRCD or a 24/192 rendering of Carmina Burana, from a live stage production. I wont go into tape or LP's here, but you can expect the same differences with those sources.
These comparisons come from Gary Pimm's system, using his second generation Tabor SS amp, with plug and play interstage and output transformer connections. None of this should be taken as faulting the Lundahl 1620, these are fabulous output transformers, Lundahl and I have just taken two different paths and thus offer different strengths.
Please note that these are very small differences and are really only available from speakers that can exceed the typical downward dynamic limit pointed to by Meyer Sound, of about 40 db below average signal levels, typical with modern dynamic speakers. Ribbon based systems and CD / LeCleach horn systems will provide greater downward dynamic range, as will any EnABL'd dynamic speaker system.
My previous statement about purchasing less revealing transformers still stands. Unless you really do have a very revealing speaker system (and of course we all are certain we do!) there is no real reason to spend from $150 to $600 per output transformer. Even if an exquisite level of signal retention and expression into your listening room is your eventual intention, I would still suggest you utilize under $100 apiece OPT's for all of your development and system proofing work, including hum and noise reduction. Then, spend your money on high resolution speakers, output transformers, speaker cables and signal sources, in that order.
Bud"
This is from the choosing a opt thread, #63 or #67...
dennis h
I have level 1. I completely agree with Bud - I've compared his transformers to Lundahls and he's absolutely right. the Lundahls are kind of more 'square'. the O-netics are softer and more detailed. More musical to me and definitely my preference. Better on classical orchestral music in particular, though right across the board really.
Andy:
My limited experience has been exactly the opposite with Level 1's. Both in sound and measurement, the Lundahl was the obvious winner. Distortion skyrocketed above 10 kHz over 1/2W-1W range, whereas the Lundahl held its ground up to around 3W. This was a Karna 300B, however, for what it's worth.
For interstages, a similar experience, but a magnitude more drastic. The O-Netics couldn't hold phase shift balance at all, even at 1 kHz. Get the series/parallel configuration right with the LL1692A (took some experimentation) and balance was good past 25 kHz.
I don't get too concerned when people opine different audible experiences; we all hear with our brains, which are all different. But the measurements made no lie, and fortunately for me I was able to hear what the scope was telling me.
My limited experience has been exactly the opposite with Level 1's. Both in sound and measurement, the Lundahl was the obvious winner. Distortion skyrocketed above 10 kHz over 1/2W-1W range, whereas the Lundahl held its ground up to around 3W. This was a Karna 300B, however, for what it's worth.
For interstages, a similar experience, but a magnitude more drastic. The O-Netics couldn't hold phase shift balance at all, even at 1 kHz. Get the series/parallel configuration right with the LL1692A (took some experimentation) and balance was good past 25 kHz.
I don't get too concerned when people opine different audible experiences; we all hear with our brains, which are all different. But the measurements made no lie, and fortunately for me I was able to hear what the scope was telling me.
I should say that my most critical listening was done with a O-netics SE transformer versus LL1620 and LL1623 in SE. I did do some listening to the PP O-netics OPT against some PP Lundahls but it was a while ago so I can't be so certain of that. So I'm being a bit general in my comparisons. I do find O-netics musical and detailed in general, and it's my daily listening 2a3 PP amp.
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