Seeking comments about Toroidy push pull output transformer for 300B project, nd would like to use 6.6K primary.
Tube output transformer [6,6kOhm]
Any good??
Tube output transformer [6,6kOhm]
Any good??
General theory behind thoroid transformers is that primary-secondary capacitance is order of magnitude higher than compared to standart EI lamination transformer, so noise from line could get through more easily.
But many use them without any problems and are quite happy about them, also these transformers are specifically designed to be used in output stage.
Try them and see if you could tell any difference.
But many use them without any problems and are quite happy about them, also these transformers are specifically designed to be used in output stage.
Try them and see if you could tell any difference.
Absolutely I use them for my mullard 5-20 builds with adjusted feddbacks and it works a treat!
The only little problematic thing is the very low frequency capabillity. Like, Ultra low. 8Hz. It could cause some LF instabillity with NFB. Thats what I experienced on my 5-20s.
These transformers are made with cintered powder cores. At least thats what I have seen. Looks pretty close to ferrite but its not ferrite.
Their transformers are practically the new high tech with no drawbacks really. Only the shipping cost.
about a power transformer, Absolutely yes go for it aswell, you might need to quote a custom transformer but they have absolutely no trouble winding you one, just give em the AC voltages under load and youre golden.
Edit: And I also own the KT88 PP transformer and its practically the best I have tried so far.
(that in terms of resonance and distortion and frequency response flatness).
Also I would recommend you this one.
TTG-CFB5000PP - Tube output CFB transformer [5kOhm] Cathode Feedback Push-pull - Shop Toroidy.pl
Its rated for 300mA idle current and its primary impedance is 5k ohm..more desireable.
And you can just leave the cathode feedback windings untouched
TTG-CFB5000PP - Tube output CFB transformer [5kOhm] Cathode Feedback Push-pull - Shop Toroidy.pl
Its rated for 300mA idle current and its primary impedance is 5k ohm..more desireable.
And you can just leave the cathode feedback windings untouched
Thanks for all information!!
My friend give me a suggestion and go for Dutch made Vlaartronic, both Toroidy and Vlaartronic costs almost the same.
My friend give me a suggestion and go for Dutch made Vlaartronic, both Toroidy and Vlaartronic costs almost the same.
Well after all it's your money and your decision. If this isn't your first build I would go for the toroids so you have something to compare them to. But I think you really can't go wrong with them.
I haven’t receipt my toroids yet, but my vote goes to Toroidy too.
Tomasz their sales man is very very kind and they are totally available to design custom trafos with all needed specs. I have changed two specs after the order and they agreed to apply the mods to the project. Five stars service!
Tomasz their sales man is very very kind and they are totally available to design custom trafos with all needed specs. I have changed two specs after the order and they agreed to apply the mods to the project. Five stars service!
Sorry I forgot to put this in my previous post.
Whether this interstage transformer suitable for the Amity??
PRODUCT PAGE
Whether this interstage transformer suitable for the Amity??
PRODUCT PAGE
IMHO, you could always make RC-coupled stage and improve it to transformer-coupled stage when you are ready. This way you can compare how different coupling methods sound on your amp and what you like better.
And since Lundhal are "the knee" in the quality curve if you can afford it - go for them, you won't be disappointed.
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Costs aside, go for a bifilar interstage. Monolith would be a proven choice that performed head and shoulders above any layered winding technique. They just have too many stray paths to resonate. Phase response is just as important as frequency response. I found the Lundahl to produce reasonable FR end-to-end, but when you look at the balance of phase from one end to the other, it was all over the place. Onetics was even worse.
Hi, I have a question concerning the transformers for EL34 ( TTG-KT88PP - Tube output transformer [4kOhm] 2xKT88 / 2x300B Push-pull or similar - Shop Toroidy.pl ) and KT88 ( TTG-EL34PP - Tube output transformer [6,6kOhm] 2xEL34 / 2x6L6 Push-pull or similar - Shop Toroidy.pl ): whilst the one for EL84 ( TTG-EL84PP - Tube output transformer [8kOhm] 2xEL84 Push-pull or similar - Shop Toroidy.pl ) has a primary capacitance of 1,3 nF, that's fair, EL34 and KT88 ones have ten times more capacitance.
I've done a simulation without gnfb, and the -3 dB point stays at around 12-13 kHz due to that capacitance.
May I have feedback from other's people about those OPTs?
I've done a simulation without gnfb, and the -3 dB point stays at around 12-13 kHz due to that capacitance.
May I have feedback from other's people about those OPTs?
I partially answer to my questions based on the feedback I've got directly by Toroidy: capacitance is localized in a small portion of the primary, so it is not correct to simulate it on its full value from anode to anode. Bandwidth of those transformers withouth gnfb (only UL connections) is 60-70 kHz at -3 dB.
I use Toroidy for PSU.
It's very good with excellent load characteristics, and we live quite close by, so delivery is real fast.
It's specially wound with 5 purpose made secondaries to my own spec.
I would never use a Toroid OPT because they sound totally different from EI, and that DOES matter.
Toroidy believe a lot in NFB windings for Cathode FB and G2 windings for ultra linear.
With that sort of idea in place, they will sound radically different from any EI system also. (obvious compression artefacts).
I don't like compression in any shape or form.
It's blindingly obvious once you have trained sound engineer's ears.
It's very good with excellent load characteristics, and we live quite close by, so delivery is real fast.
It's specially wound with 5 purpose made secondaries to my own spec.
I would never use a Toroid OPT because they sound totally different from EI, and that DOES matter.
Toroidy believe a lot in NFB windings for Cathode FB and G2 windings for ultra linear.
With that sort of idea in place, they will sound radically different from any EI system also. (obvious compression artefacts).
I don't like compression in any shape or form.
It's blindingly obvious once you have trained sound engineer's ears.