Just to be clear, this box isn't a reactive load, it's an impedance matching device to take the speaker output and convert it to a form of a DI box. I.e. lower the output of the speaker to something you can put into a mixer directly. Putting a line level input into a speaker is going to not work well at all. It would be super weak.
pompeiisneaks wrote: ↑Mon Dec 03, 2018 4:54 pm
Just to be clear, this box isn't a reactive load, it's an impedance matching device to take the speaker output and convert it to a form of a DI box. I.e. lower the output of the speaker to something you can put into a mixer directly. Putting a line level input into a speaker is going to not work well at all. It would be super weak.
~Phil
Sorry, yeah... this is the cut sheet from the Jensen audio transformer.
I was wanting to know why they chose the values they did for the ground lift resistor/cap
purely an academic question since is the load is built.
Last edited by Cathode Ray on Mon Dec 03, 2018 5:30 pm, edited 1 time in total.
pompeiisneaks wrote: ↑Mon Dec 03, 2018 4:54 pm
Just to be clear, this box isn't a reactive load, it's an impedance matching device to take the speaker output and convert it to a form of a DI box. I.e. lower the output of the speaker to something you can put into a mixer directly. Putting a line level input into a speaker is going to not work well at all. It would be super weak.
~Phil
Sorry, yeah... this is the cut sheet from the Jensen audio transformer.
Oh gotcha, so you just ran across this one and were curious.
sluckey wrote: ↑Mon Dec 03, 2018 6:08 pm
That exact same ground lift circuit with same component values can be found in one of KOC's books. I bet Jensen copied that from him.
The idea behind the standard E values is that every jump in value is the same percentage larger than the previous value... the jump from 1 to 1.5 is roughly the same percentage increase as the jump from 6.8 to 10 and again from 10 to 15. It actually makes a ton of sense once you wrap your head around it.
The idea behind the standard E values is that every jump in value is the same percentage larger than the previous value... the jump from 1 to 1.5 is roughly the same percentage increase as the jump from 6.8 to 10 and again from 10 to 15. It actually makes a ton of sense once you wrap your head around it.
I hit an online auction a while back from a local hearing aid test equipment company that was moving manufacturing overseas ( ) and bought a lot of three of those multi-drawer electronics parts boxes. By the look of things they were from three different workstations, mostly 1/4w resistors with a random selection of caps and the occasional op amp, etc... Anywho, because it was different stations, there was a ton of overlap in values so I spent a few afternoons sorting and combining, and I ran across that webpage while working through that. Talk about a quick way to get familiar with standard values! There were a few random gaps, but I've basically got full E24 coverage in carbon comp 1/4w. Pretty handy for pedal building, even if I tend to go heavier in my amps. Definitely worth the effort. I also scored a Tektronix 2445B that seems to function perfectly... not bad for the $200 I spent at that auction!
) and bought a lot of three of those multi-drawer electronics parts boxes. By the look of things they were from three different workstations, mostly 1/4w resistors with a random selection of caps and the occasional op amp, etc... Anywho, because it was different stations, there was a ton of overlap in values so I spent a few afternoons sorting and combining, and I ran across that webpage while working through that. Talk about a quick way to get familiar with standard values! There were a few random gaps, but I've basically got full E24 coverage in carbon comp 1/4w. Pretty handy for pedal building, even if I tend to go heavier in my amps. Definitely worth the effort. I also scored a Tektronix 2445B that seems to function perfectly... not bad for the $200 I spent at that auction!