alexberger
Responses from alexberger
| Metal or Carbon Resistors - Which is better? A 300B amplifier can sound dynamic if it has a properly designed driver circuit. The 300B tube is much more difficult to drive than 2a3, 45 and px25. It needs more voltage amplitude and current. The interstage transformer or direct coupling catho... | |
| Metal or Carbon Resistors - Which is better? I wanted to share my resistor preferences for different applications. I prefer using tantalum resistors in signal paths and cathodes. For power supplies, I opt for metal film resistors. Lastly, for loads, stoppers, and speaker crossovers, I fin... | |
| 300b lovers Hi @lynn_olson , I think the Hashimoto a-305 is an extraordinary transformer. The measured frequency response of this transformer (with 6f6) in my amplifier is 6Hz to 90KHz -3dB. The difference in sound between RC coupling and this IT was huge, i... | |
| 300b lovers Hi @lynn_olson , I’m working on my DIY 300B SET amplifier, which has three stages coupled by transformers. The first stage uses 1/2 6sn7, and I’ve been experimenting with different driver tubes: 6f6, 6v6, and 5881. I’ve noticed that the more powe... | |
| Tannoy Turnberry vs Fyne 502SP? I haven't seen Frank and Coherent speakers on Montreal audio show this year. I think they weren't present this year, or I missed something. | |
| 300b lovers Hi @atmasphere I just found schematics with a cathode follower 12BH7 300B driver. Is it similar to the schematics you were talking about? https://www.diyaudio.com/community/threads/300b-schematic-recommendations.340133/page-2 Just don't nee... | |
| New Jupiter Comet and VitaminQ Silver PIO Capacitors The Duelunds speaker crossover inductors 1.5mH pair (for my Altec 604E n1500 crossover) will cost $750 WAX and $700 Cust. Not cheap. The Jantzen Wax Coil that I use now cost me just $150. I use a Duelund silver bypass in the same crossover to byp... | |
| COINCIDENT FRANKENSTEIN 300B STEREO Hi @mclinnguy Which speakers do you use with this amplifier? | |
| Your journey with lower-watt tube amps -- Can a kit be good enough? Hi @invalid , Yes most of vintage amplifiers use chokes in power supply. But they use very small capacitors in B+. The issue with small capacitors is not the 120Hz noise from AC , but voltage stability during playing of load and complex music. | |
| Revisiting Chinese Knockoff Cables Here are a number of updates. I have mixed impressions with Chinese cables so far. I compared again my 25 years old Acrotec 8N 2080 mk1 to Odin Gold RCA cable. Yes, Odin Gold is nice, musical and well balanced. But it is clearly inferior to the ... | |
| Your journey with lower-watt tube amps -- Can a kit be good enough? Hi @atmasphere , Power supplies of all vintage tube amplifiers from 50-60x look so miserable with such small capacitors. It is especially true for stereo amplifiers when PS is used for both channels in parallel without any separation. I can say... | |
| Your journey with lower-watt tube amps -- Can a kit be good enough? Hi @atmasphere , In parallel to the McIntosh MC30 I had Marantz 8b. I used these amplifiers with Spendor 2/3 and Altec 604E with original n1500 crossovers. This Marantz was burned by one of the previous owners. So output transformers were fixe... | |
| Your journey with lower-watt tube amps -- Can a kit be good enough? I had Spendor 2/3 speakers for around 5 year. A number of years I used the Plinius 8200 integrated to drive these speakers. But I felt something was wrong and I started looking for a good matched amplifier. I stopped on the McIntosh MC30 vintage m... | |
| Your journey with lower-watt tube amps -- Can a kit be good enough? Hi @atmasphere Thank you for your advice. I can try it if I build a new amplifier. So. Do you think the issue is not voltage swing of driver but the current and power it should drive on capacitive load. And the power is function of the voltage ... | |
| Your journey with lower-watt tube amps -- Can a kit be good enough? Hi @hilde45 The problem of 300B they need a driver with 150 volt peak to peak voltage swing. For 845 you need much more voltage swing. It is possible to drive 845 with RC coupling, but you get much more distortions vs IT drivers with the same... |