In my opinion, DC coupled amplifiers require correction, detection and protection circuits to ensure reliable speaker/s.
That equates to:
DC servo
and
DC detection
and
amplifier shutdown
if the DC wanders away from your preferred maximum output offset.
That equates to:
DC servo
and
DC detection
and
amplifier shutdown
if the DC wanders away from your preferred maximum output offset.
In theory then, a DC coupled buffer driving an AC coupled power amplifier fitted with a blocking cap should be a fairly safe combination, especially if the power amplifier has speaker protection built in like the My-Ref FE?
Yes, in theory and in practice, an AC coupled amplifier prevents input DC from damaging speakers.
Using the DCB1 as opposed to the vanilla B1 to feed an AC coupled amp removes *one* set of blocking caps.
So then *generally* we could say that the purpose of a DCB1 is to feed an AC coupled amplifier, and it is recommended that blocking caps are installed to feed a DC coupled amp that has NO DC protection.
Would an input transformer also block DC? Say a transformer to converts a Single ended to Balanced input?
So then *generally* we could say that the purpose of a DCB1 is to feed an AC coupled amplifier, and it is recommended that blocking caps are installed to feed a DC coupled amp that has NO DC protection.
Would an input transformer also block DC? Say a transformer to converts a Single ended to Balanced input?
That's something I don't really get, would a transformer not potentially negate any possible gain made by going balanced?
Depends on source, load and signal level but maybe LL1684 could be something for you.
Other Tube Transformers | Product Categories | Lundahl Transformers
Other Tube Transformers | Product Categories | Lundahl Transformers
It is possible for comparable Yfs and IDSS JFETs. I don't know the 2SK163 specifics. I thought it was a Mosfet?
If talking about this NEC obscure NOS part that I got this datasheet in my files on the other hand, I see low transconductance vs. K170. It would not be much different in M selection than using a 2SK117BL for instance. No modifications, it will play, just not as great as a K170BL.
If talking about this NEC obscure NOS part that I got this datasheet in my files on the other hand, I see low transconductance vs. K170. It would not be much different in M selection than using a 2SK117BL for instance. No modifications, it will play, just not as great as a K170BL.
Hi Salas, Thanks for reply.
I search on Google and find 2SK163 is manufactured by NEC. N channel JFET low noise audio amplifier. The datasheet is same with your attachment.
I have to collect some other component and then make a PCB. I will try to build DCB1 with SK163. in local store near my home I can get SK163, but there is no stock SK170. I think it will be interesting 😀
I search on Google and find 2SK163 is manufactured by NEC. N channel JFET low noise audio amplifier. The datasheet is same with your attachment.
I have to collect some other component and then make a PCB. I will try to build DCB1 with SK163. in local store near my home I can get SK163, but there is no stock SK170. I think it will be interesting 😀
Notice they are L or M selection, else avoid. You will need high L or low M IDSS so to have pairs around 9-11mA for having some meaningful gm for DCB1. Where are you located and finding such in a store still?