ndevamp
Responses from ndevamp
| Futterman. Jump in? Or, not so fast... Roger and I had some great discussions way back when about Futterman circuits. The genius was getting a pentode to operate at low plate voltage with high screen voltage, operated by a bootstrapped driver pentode. The oscillations partly came from ... | |
| Sansui CA 2000 preamp Glad it fits into your system well! Especially regarding the low noise with sensitive speakers. A low powered amp would work well with them and a single ended tube amp might work well. At 100dB efficiency all you might need would be a 300B amp wit... | |
| Through unfortunate circumstances........ To use your Yamaha HTR-5660 with your Pioneer Spec 1 preamp, you’d run an interconnect from the main RCA output of your receiver (the main output rca sockets are just above the left hand side of the speaker outputs), to an aux input or tape input ... | |
| Balance knob .. Is it a speaker positioning problem, or an amplifier etc. problem? I’d try to work out where the problem lies before resorting to use of a balance control.Try swapping the channels at the speaker leads to see if the balance issue swaps channels. I... | |
| EAR founder has cancer Oh. Poor Tim!Better go and see him properly soon, he’s here in the UK. But chatting to him isn’t straight forward, I’ve learned. We’ve had some great chats over the decades. I was only wondering the other day after seeing him at Munich last year w... | |
| Sansui CA 2000 preamp Should be a nice preamp. It was one of the first to incorporate low distortion transistor circuitry, and had a unique volume control circuit that reduced noise to very low levels. They don’t make them like that anymore and from that standpoint, it... | |
| What's wrong with variable bias? Looking at the schematic, the TA-A1ES switches the quiescent bias current from low to high depending on volume output. At low volume it uses low bias to save on heat output from the output transistors. Both halves (both NPN and PNP output transist... | |
| Nakamichi CA-7A & CA-7E difference Looking at the schematic, there were a few versions made of the CA-7E. The UK one was set for 240V, the German and European one set for 220V (can be changed to 240V internally). Both those can’t be set for 120V operation. Only the Saudi Arabia ver... | |
| impedance matching buffer Perhaps try a transformer volume control. It’s passive and because it’s a transformer, it will maintain low output impedance. Antique Sound Labs make a nice one, T2 DT. | |
| Review: Sansui AU-7700 Amplifier I’ve had a few Sansuis over the years. The AU-9500 was superb and a pleasure to use. It needed restoring a few years back, some of the transistors became noisy so I replaced them. The switches all needed cleaning, and the volume control needed rep... | |
| Anyone done A / B listening to compare vintage stereo receivers with today’s Amps/Preamps? Echolane, +1 for moving the switches regularly to keep them working well.I help maintain a studio mixing console with hundreds of mechanical switches. The advice given in the service manual is to do just that, operate them regularly to keep tarnis... | |
| Anyone done A / B listening to compare vintage stereo receivers with today’s Amps/Preamps? Just keep a spray can of switch contact cleaner handy when you notice a switch giving issues. | |
| Anyone done A / B listening to compare vintage stereo receivers with today’s Amps/Preamps? I agree with mrdecibel, there are generally lots of switches with the audio signal going through them in older gear. There are some issues with that.Apart from the extra wiring needed to get the signal from the circuit board to a front-mounted swi... | |
| Anyone done A / B listening to compare vintage stereo receivers with today’s Amps/Preamps? Things that have changed over the years are: solid state parts were designed as through-hole components, now mostly surface mount and integrated circuits. That makes the assembly a lot more compact and so eg. circuit board inductance reduces, allo... | |
| 12BZ7 ///12AX7 The BH/BZ/AX data sheets all look similar in the same way that a bicycle is similar to a motorbike. They have the same number of wheels and you need to balance to ride them.Well if nothing else you’re enthusiastic about it all! But don’t be disapp... |