as Will said - gain is strictly by autoformer action, settable between 0db, +2db, +4db, +6db, +8db
no; it is as it is; that's why I developed fully balanced Iron Pumpkin
it contains rare beast - fully differential autoformer volume control module
as explained in principle on first page of this very thread, with rest of shebang, there is a choice of enabling inputs either as SE or Bal, and at inputs there are both SE and Bal at disposal, even used in same time
typo and unclear
needs to be :
as explained in principle on first page of this very thread, with rest of shebang, when speaking of Balanced iteration - there is a choice of enabling inputs either as SE or Bal, and at output are both SE and Bal at disposal, even used in same time
as its "name" sez;
heard anywhere for SE preamp having balanced inputs and/or outputs?
SE, by nature, can have just SE, while Bal can have both
completely normally, per physics - Rout is buffer Rout (low, 30-ish) multiplied with impedance ratio of actual gain setting; impedance is squared voltage; so - for 6db goes 4-times impedance
I believe practically all questions are answered and even covered with some measurements, both here and here: https://www.diyaudio.com/community/...egetable-animals-tips-n-tricks-thread.336114/
in short - whatever overall gain setting is and whatever actual vol. position is - Iron Pumpkin is having very low THD ........ not much of change in sound whatever varied
one exception - +8db setting is to avoid for case of SE Input to Bal Output, with amps of lowish Rin; that's just too much for one buffer to pump up
any other combination is non-critical, you can drive even a nail in wood
edit: worth saying that Rout of Beastie is easy to calculate ........ and it is divided down for each volume setting actually being bellow input voltage; each step of 24 (1 to 24 max) is being 2db
so - if gain set to 0db and vol set to -6db (pos. 21) Rout is 30-ish divided with 4
you can easily drive cans or small desk speakers ....... tried and dusted
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Dan K - as you attenuate, the output Z of an autoformer quickly approaches 0.
These transform energy, rather than throwing it away by turning it into waste heat as with any of the resistive controls. It kind of "supercharges" the drive capability of the source. The subjective improvement is particularly noticeable at low to mid listening levels.
These transform energy, rather than throwing it away by turning it into waste heat as with any of the resistive controls. It kind of "supercharges" the drive capability of the source. The subjective improvement is particularly noticeable at low to mid listening levels.
that, vs. regular resistive attenuating schemes
not that Iron Pumpkin is sounding worse at higher volume settings ........
I've been doing my research, but I'm still not 'getting it'..
What are the gain settings on the iron turtle actually doing? Are they simply moving the starting point of the output taps? Do they select different input taps? Confused..
If I want to listen at at 70dB then should I have the gain set at 0 and the dial at 9 o'clock, or the gain at +8dB and 7 o'clock on the dial? Do each of these settings give exactly the same result?
Is there a particular combo that will give the perfect impedance 'match' for my power amp?
Using an M2 and Snell J2's
What are the gain settings on the iron turtle actually doing? Are they simply moving the starting point of the output taps? Do they select different input taps? Confused..
If I want to listen at at 70dB then should I have the gain set at 0 and the dial at 9 o'clock, or the gain at +8dB and 7 o'clock on the dial? Do each of these settings give exactly the same result?
Is there a particular combo that will give the perfect impedance 'match' for my power amp?
Using an M2 and Snell J2's
yes, so when you choose max volume, you're "above" input signal level, so autoformer action is adding voltage
stare at pic in post #4, this thread https://www.diyaudio.com/community/...smaller-vegetable-animals.311852/post-5175544
with M2, you'll never need setting to have gain, 0db is enough
sound difference between different gain setting are negligible, practically
dobbel checking, this work with the pumpkin?
rectifier https://www.digikey.no/no/products/detail/genesic-semiconductor/DB101G/3927712
zener diodes
https://www.digikey.no/no/products/detail/onsemi/1N4148/458603
https://www.digikey.no/no/products/detail/onsemi/1N5250BTR/977617
Andreas
rectifier https://www.digikey.no/no/products/detail/genesic-semiconductor/DB101G/3927712
zener diodes
https://www.digikey.no/no/products/detail/onsemi/1N4148/458603
https://www.digikey.no/no/products/detail/onsemi/1N5250BTR/977617
Andreas
Hi Zm
dobbel checking again, are this ok ?
dobbel checking again, are this ok ?
- IC2 7805. https://www.digikey.no/no/products/detail/umw/L7805CV/17635308
- IRF9510 https://www.digikey.no/no/products/detail/vishay-siliconix/IRF9510PBF/811789
- IRF510. https://www.digikey.no/no/products/detail/vishay-siliconix/IRF9510PBF/811789
- what about C5-C6 can’t find them anywhere on the mobo schematic.
- Quasimodo capacitors and resistor, is this something I need with the xformers from you ? and if what values.
^ I can help a bit with above.
All parts linked. Yes.
C5 and C6 are SMD, pre-installed by ZM and on the bottom of the MoBo.
re: snubber - those will depend on the transformer you choose. If you don't have a Quasimodo to measure your transformer, then you can maybe find the answer in this thread.
https://www.diyaudio.com/community/threads/quasimodo-results-only.313202/
All parts linked. Yes.
C5 and C6 are SMD, pre-installed by ZM and on the bottom of the MoBo.
re: snubber - those will depend on the transformer you choose. If you don't have a Quasimodo to measure your transformer, then you can maybe find the answer in this thread.
https://www.diyaudio.com/community/threads/quasimodo-results-only.313202/