Read the thread. This was debated before. E-I cores naturally have a small gap. This core is VERY over-size for a 20W SE amp. Distortion measures show no bass distress.
damn... didn't see that zener exist 😀
it's all good now, i put the zener and everything is normal.
thanks ZM
anyway this zener does affect the sound, i like without it.
but no choice when using big transformer, must be installed.
normal , that's Ugs voltage
try higher zener voltage , if you believe you hear it in system
or out string of lesser voltage ones (2V5? 2V7?) , counting on lesser capacitance
try higher zener voltage , if you believe you hear it in system
or out string of lesser voltage ones (2V5? 2V7?) , counting on lesser capacitance
What about a speaker protection?
[speaker protection]
Hi all.
I'm building a couple of Big MoFo. While a Bride of Zen is on the road, I'm actually using an old dual mono tube preamplifier as gain stage to perform some test and measure. I find the sound is great/marvelous//astonishing so I'm thinking about how to finalize it.
One of the item on the list is the speaker protection. I know that we already have a 6800uF output capacitance that should block any DC component to the speakers, but I feel more comfortable with a protection against "on/off bump" and so on.
Does anyone use such a protection or is it unuseful or even dangerous since it would let the [big]MoFo work without a load for (at least) some seconds?
Thanks in advance,
Claudio
[speaker protection]
Hi all.
I'm building a couple of Big MoFo. While a Bride of Zen is on the road, I'm actually using an old dual mono tube preamplifier as gain stage to perform some test and measure. I find the sound is great/marvelous//astonishing so I'm thinking about how to finalize it.
One of the item on the list is the speaker protection. I know that we already have a 6800uF output capacitance that should block any DC component to the speakers, but I feel more comfortable with a protection against "on/off bump" and so on.
Does anyone use such a protection or is it unuseful or even dangerous since it would let the [big]MoFo work without a load for (at least) some seconds?
Thanks in advance,
Claudio
Big MoFo and its ZENER
Hi all.
One more question is about the zener diode that's mentioned on the document.
I tried also searching on this thread but I didn't find a specific and CLEAR information. So:
1) where should this zener be placed exacly? Since I cannot find a schematic, it would be really nice to see one 🙂
2) in case of Big MoFo, should the zener be 20V/5W or something else?
3) most of all: does the zener impact audio performance? 🙄
Thanks in advance,
Claudio
Hi all.
One more question is about the zener diode that's mentioned on the document.
I tried also searching on this thread but I didn't find a specific and CLEAR information. So:
1) where should this zener be placed exacly? Since I cannot find a schematic, it would be really nice to see one 🙂
2) in case of Big MoFo, should the zener be 20V/5W or something else?
3) most of all: does the zener impact audio performance? 🙄
Thanks in advance,
Claudio
it is on pcb and I explained how it is connected in circuit
no need for speaker delay or connection
MoFo doesn't care is load connected or not
no need for speaker delay or connection
MoFo doesn't care is load connected or not
Thanks for your reply. Just to be sure: must the zener in BIG MoFo be 20V like in normal MoFo?
anything between 7V5 and 20V will do the job , even if I would stay with 18V as max value
it's there to ensure that Ugs is never higher than breakdown voltage .......... which is for IRFP150/250 in range of 20V positive
you have same danger in negative , but there negative peak is hardly expected
it's there to ensure that Ugs is never higher than breakdown voltage .......... which is for IRFP150/250 in range of 20V positive
you have same danger in negative , but there negative peak is hardly expected
I’m currently collecting parts to build the MoFo and I wonder if it’s worthy to go for more high end chokes? I mean, is it audible when using for instance a Lundahl choke instead of the Hammond?
This is the measure I took on Sunday on my big MoFo, with the "cheap" Hammond 193V. I really don't think a more expensive choke is required. 😉
2k and 20k square waves on 8 ohm resistive load.
