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.
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
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
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.
