hhmmm no sony... had some when had a vfet to repair some time ago but naah got none of those also some 10p??? whatever it is comp pairs. or BU??? 906??? seen a list on here them ones!!!!! I have Rauch DVT's so this circuit arrangement or topology is not new to me 20+yrs on MST-Rauch did work for the distributor as well as knew the MD. Ben Duncan did the SRS SMPS for it. sound like your Goldmun thingy very fast but for pro-use bandwidth limited. very light weight although have modded one in the past to linear PSU for a friend.
Hi Zen
I got 2 talema 2x45vac 10A can this transformer power this goldmund ?
what should i do ?
Thank you before
Selamat Pagi Jacco
this is the Transformer, Toroidal,500VA,0-230V pri 50/60Hz,2x0-45V sec
you can look the link here
Nuvotem | Transformers | Transformers | Toroid Transformers | Toroidal Encapsulated 230Vac Primary 15VA to 500VA |0500P1-2-045K
Thank you before, Best Regards
Golmund clone
2N5565 Motorola
BC 546B National
BC 182B Motorola
MPSA 93-43 Motorola
BSS71-BSS71 Motorola
Double Voltage
Positive rail 84.05V
Negative rail 82.03V
Pre-flight test joint R21 on Vas stage T8.
T11-12 out of board
Offset=0-3mV
R1=3.177V
R2=3.180V
R3=74mV
R4=76mV
R5=6V
D1=5.96V
R16=980mV
R14=481mV
R15=496mV
R17=2.090V
R18=2.200V
On resistor R23=1.8V
Square wave test 1KHZ , 10KHZ , 100KHZ
2N5565 Motorola
BC 546B National
BC 182B Motorola
MPSA 93-43 Motorola
BSS71-BSS71 Motorola
Double Voltage
Positive rail 84.05V
Negative rail 82.03V
Pre-flight test joint R21 on Vas stage T8.
T11-12 out of board
Offset=0-3mV
R1=3.177V
R2=3.180V
R3=74mV
R4=76mV
R5=6V
D1=5.96V
R16=980mV
R14=481mV
R15=496mV
R17=2.090V
R18=2.200V
On resistor R23=1.8V
Square wave test 1KHZ , 10KHZ , 100KHZ
Attachments
Golmund clone
100KHZ
And after correction
1KHZ- 10KHZ- 100KHZ
Until to be completed and the output stage is a long way to go.
I have little concern about the noise - hum when the amplifier enters the box because it hasn't star ground on ground plane and it will take some cuts on ground plane to properly isolated.
100KHZ
And after correction
1KHZ- 10KHZ- 100KHZ
Until to be completed and the output stage is a long way to go.
I have little concern about the noise - hum when the amplifier enters the box because it hasn't star ground on ground plane and it will take some cuts on ground plane to properly isolated.
Attachments
Last edited:
hi ashok, mostly observing this obession with with this "souped up" Hitachi amp, but that should give you a clue!!! it sounds like a hundred other amps of very similar topology.... just in varying degrees..but for the most part it all in how you set it up topology wise if you want a pretty one but an old HMA 7500 MkI or MkII a little bit of modding the original circuit will give you a pretty good looking "Goldmund" still fascinated by all this respect is due!!!
Bullocks, imo.
Differentiating between a GM and e.g. a Sphinx PJ12 MKI (also monaural, high bandwidth, JFET differential input stage, 3 pairs of J50/K135 Hitachi laterals) will not be that straightforward.
But calling an upgraded Lo-D 7500 a Goldmund means you've never seen or heard the Frenchy amp.
!!!!! not too sure about that I used to be a high end hi-fi reseller as well as being a very capable audio engineer.
this amp is a "Hitachi" topology amplifier that has been inverted, the additional mod of the fets is not a new thing to me neither is how this circuit behaves did this experiment over 20 yrs ago. as for its relative performance choosing appropriate components for both characteristics and or value and their effect on the subjective audio can be applied to many topologies with similar results the quality of the "sound" can be altered to suit or mimic. a few years back I handled some of the service duties for a distributor of pro-audio products inc Carver, MST rauch, Australian monitor, IRP, Ashly. had much contact with Bob carvers work where his work on "T.F.M." was quite interesting. so heres the rub take one Goldmund amp circuit mess about with it a little to what purpose why not just go and buy one???
I must be really missing something here it is not hard to get "good quality sound" from this "inverted Hitachi" with its new differential pair.
I have managed to gain preference over a "Krell KSA100" with an amp using a "non-inverting Hitachi" circuit with ease using 2N5401's as the input diff pair. so what is all this 1500+ posts on this device coz I am definitely not fully understanding the point of it. a applaud the circuits simplicity always a good point to design a circuit that does not by its own topology create further issues that need yet more stuff incorporated into it to correct them.
choices of different devices that different people use and suggest to others are purely subjective opinions as to their performance with their sources in their own unique environment or must one apply the same stringent rules to this end.
at the end of the days the results of this project are pretty much subjective are they not? please please explain to me someone a concise explanation on this thread and its purpose coz I honestly cannot get it
sorry what is a GM or a sphinx pj12mkI???? whats a LO-D 7500??? think you are trying to tell me this circuit is complex??? coz its not can draw it from memory along with it values even some of the test point potentials and PD's easy to make a "Hitachi HMA 7500" or even a 6500 sound or perform like this "Goldmund" they are so almost the same they could be twins!!!!
BTW I am quite new to forums entirely
price tag??? for what? if you mean an amp to buy, I never buy other peoples amps for personal use. but for business yes no problem used to buy racks full of them to hire.
but if its for my listening pleasure no way 99.999999% are not good enough so make my own for that. perhaps I should do a layout for this device try it but pretty sure it will be the same thing I have done so long ago
so price tag??? if we a talking this goldmund thing most esoteric high end stuff has an inflated price way above any reasonable costing. but then thats what creates its kudos cheap is nasty or no good whereas expensive must be good as well as unavailable to many marketing trick.
actually my son and I were considering manufacturing amps made of glass ( the casing and heatsinking as well) just because people will pay small fortunes for such things check out all the glass loudspeakers there are on the market. are they good?
do they sound "good" one mans good is anothers junk it is purely subjective on the man!!!! so still not getting it. why are you building it? why not design your own or is mimicry the fundamental purpose here?