etheory
Well-known member
Hi there!
I've had had an inkling for some time now to try and simulate the Neumann PEV amplifier circuit in LTSpice, mostly because A.) I'd really love to build one and B.) I wanted to verify that with currently obtainable parts, it should be possible to do one seriously sweet clone.
Well, it kinda looks like it's working. It's certainly amplifying, and seems to do so relatively cleanly ( until you get up to like 1V RMS on the input, at which point it starts to clip, but it looks like quite a soft clipping ). There are more details to figure out for sure, but has anyone else ever built one of these things?
If anyone has any solid information on the iron I'd be most obliged. Especially modern replacements for the input, inter-stage and output transformers.
The actual amp itself seems to be a relatively straight forward symmetrical affair - almost Neve'ish in implementation. I am going to mess with a few transistor replacements and see whether I can match the same performance, but it looks like a viable build ( at least to SOME degree of keeping the original vibe ).
Does anyone else have any experience they could share with me about these - especially some actual measurements of the transformers? For the "transformers" in the sim, even just whacking a series resistance of 3ohms and 3H inductance per mutual winding, the sim chugs along OK. Obviously with more accurate data I could do a better simulation.
BTW, here it is.... The Green trace is a test 100Hz input at +-100mV, and the blue is the amplified output. Source and Load are both set in this simulation to 600ohms. The "wobble" at the start is expected ( most equipment does this at power on anyway due to charging caps ) and goes away after a second of the simulation.
I've had had an inkling for some time now to try and simulate the Neumann PEV amplifier circuit in LTSpice, mostly because A.) I'd really love to build one and B.) I wanted to verify that with currently obtainable parts, it should be possible to do one seriously sweet clone.
Well, it kinda looks like it's working. It's certainly amplifying, and seems to do so relatively cleanly ( until you get up to like 1V RMS on the input, at which point it starts to clip, but it looks like quite a soft clipping ). There are more details to figure out for sure, but has anyone else ever built one of these things?
If anyone has any solid information on the iron I'd be most obliged. Especially modern replacements for the input, inter-stage and output transformers.
The actual amp itself seems to be a relatively straight forward symmetrical affair - almost Neve'ish in implementation. I am going to mess with a few transistor replacements and see whether I can match the same performance, but it looks like a viable build ( at least to SOME degree of keeping the original vibe ).
Does anyone else have any experience they could share with me about these - especially some actual measurements of the transformers? For the "transformers" in the sim, even just whacking a series resistance of 3ohms and 3H inductance per mutual winding, the sim chugs along OK. Obviously with more accurate data I could do a better simulation.
BTW, here it is.... The Green trace is a test 100Hz input at +-100mV, and the blue is the amplified output. Source and Load are both set in this simulation to 600ohms. The "wobble" at the start is expected ( most equipment does this at power on anyway due to charging caps ) and goes away after a second of the simulation.