Search found 1839 matches
- Mon Jan 23, 2023 8:05 am
- Forum: Technical Discussion
- Topic: LND150 replacement options
- Replies: 29
- Views: 3343
Re: LND150 replacement options
I like the IRF style devices as a loop follower. On the return side the LND-150 is great. Unfortunately, most suppliers are talking late 2023 for stock again. I agree, nowadays there are probably better options than the IRF series, but as a general concept I prefer to have a device that can handle ...
- Mon Jan 23, 2023 7:57 am
- Forum: Technical Discussion
- Topic: LND150 replacement options
- Replies: 29
- Views: 3343
Re: LND150 replacement options
That particular device is going down the way of the dinosaur, so it may not have been the best example. So you call that prehistoric when you in 2023 propose a very dangerous schematic with an IRF820 that is more than 40 years old? :D Don't make your bitterness hide your brain. A device can either ...
- Sat Jan 21, 2023 11:45 pm
- Forum: Technical Discussion
- Topic: LND150 replacement options
- Replies: 29
- Views: 3343
Re: LND150 replacement options
They do operate very well when used in a cascode configuration, however. LND150's also work very well when used in cascodes. If two devices are needed for the return, I absolutely drive them from the source through a pmosfet and give feedback from drain to the gate to triodize the curves. Sounds wa...
- Sat Jan 21, 2023 11:41 pm
- Forum: Technical Discussion
- Topic: LND150 replacement options
- Replies: 29
- Views: 3343
Re: LND150 replacement options
Why not? They work fine as source followers as do a wide array of other devices. Their small size and sufficient no-heatsink wattage make them ideal for source followers. There are other components that do source following way better than them, EG the STU9HN65M2 able to strongly drive even heavy lo...
- Sun Jan 15, 2023 9:11 pm
- Forum: Technical Discussion
- Topic: LND150 replacement options
- Replies: 29
- Views: 3343
Re: LND150 replacement options
I would not use then on the buffering send stage of the loop, instead other choices like the very old IRF820 or modern upgrades are better. For the return stage both a DN2540 or a DN3545 can be used. Check an high voltager depletion mosfet on major sites and pick the one available, then play with it...
- Fri Jan 13, 2023 1:39 pm
- Forum: Technical Discussion
- Topic: Output Transformer primary impedence
- Replies: 3
- Views: 519
Re: Output Transformer primary impedence
It would most probably give too much 2nd harmonic. You could try it and play with the PSU to lower the voltage, increase the current through the tube and find a sweet spot for that tube. Another option could be to install an EL34 to fully use the 5k instead of the 8k, if the PT can give enough curre...
- Wed Jan 04, 2023 11:25 pm
- Forum: Technical Discussion
- Topic: 10K screen grid resistor?
- Replies: 12
- Views: 1202
Re: 10K screen grid resistor?
It could be used as an "effect" on the power amp, causing strong compression when the secondary emission takes place.
Another reason could be that they developed the amp using tubes with weak screen grids, so they protected them this way.
Another reason could be that they developed the amp using tubes with weak screen grids, so they protected them this way.
- Sun Jan 01, 2023 6:30 pm
- Forum: Technical Discussion
- Topic: Single Ended Amps - Opinions
- Replies: 91
- Views: 12649
Re: Single Ended Amps - Opinions
Before the coupling cap.
- Fri Dec 30, 2022 7:09 pm
- Forum: Technical Discussion
- Topic: Cathode follower for compression
- Replies: 11
- Views: 1311
Re: Cathode follower for compression
Thanks, why back to 100K at higher volumes? What you do by lowering the 100k to 47k is exacerbate the compression of the stage at lower volumes. When you crank the volume, you will find too much compression, and need to go back to 100k (or at least increase this value). Please note that this is val...
- Thu Dec 29, 2022 1:36 pm
- Forum: Technical Discussion
- Topic: Cathode follower for compression
- Replies: 11
- Views: 1311
Re: Cathode follower for compression
I'm not sure we are talking about the same mod because I'm not familiar with the specific reference, but I modded some Bassman in the past by lowering the cathode follower resistor from 100k to 47 to 68k depending on the taste of the owner of the amp. It was switchable with the amp not running (beca...
- Mon Dec 19, 2022 9:01 pm
- Forum: Technical Discussion
- Topic: Hum neutralizing circuit
- Replies: 11
- Views: 1719
- Mon Dec 19, 2022 10:46 am
- Forum: Technical Discussion
- Topic: CUSTOMAUDIO OD100
- Replies: 20
- Views: 3615
Re: CUSTOMAUDIO OD100
Interesting, so it still has the 2.7K/.22uF bypass on the 3rd stage? I thought the standard had less gain than the OD100SE. One of the lead channel I liked most was developed together with a friend on the CAE 2nd and 3rd cold stages with partial bypass. First two coupling caps were (IIRC) scaled do...
- Fri Dec 16, 2022 12:13 pm
- Forum: Technical Discussion
- Topic: CUSTOMAUDIO OD100
- Replies: 20
- Views: 3615
- Thu Dec 15, 2022 3:42 pm
- Forum: Technical Discussion
- Topic: CUSTOMAUDIO OD100
- Replies: 20
- Views: 3615
Re: CUSTOMAUDIO OD100
I copy here some comments written by bnouille (Bruno Durand IIRC): OD100 SE+ is just basically the same as the 3+ .Same clean and lead channel .The so called "crunch" channel is just the lead channel with one R value lowered for less gain somewhere ( can't remember which one cause it's been a long t...
- Thu Dec 15, 2022 10:51 am
- Forum: Technical Discussion
- Topic: CUSTOMAUDIO OD100
- Replies: 20
- Views: 3615
Re: CUSTOMAUDIO OD100
I've now seen you have a site and you build Dumble-like amps.
I think the best option for you is to ask directly to a forumer called "Husky" (should be here too) for an official reply.
It can also be a better reference for the customer, even more if he is a tournist.
I think the best option for you is to ask directly to a forumer called "Husky" (should be here too) for an official reply.
It can also be a better reference for the customer, even more if he is a tournist.