This is a really cool idea. It could be very useful as a diagnostic tool to track down noise, or check for a bad tube in a preamp. I couldn't really tell from the video if the transistor had any appreciable hum or hiss though.
I can't recall off the top of my head, but I think if I had of noticed excess noise, I would of said something in the video. In practice, they can fill a role. One position in my Jubilee greatly improved the amp overall.
Hah, it does work in a pinch, I'd hardly say it works as well as tubes, and unless you craft some way to securely mount the fets in the socket, it could be a bad time.
LND150s are the shit. Running them as gain stages at high voltage in pedal designs makes the most dynamic response ever. The reason solid state doesn't sound or feel as good as tubes is because of the low voltages, not because of the sand. But using solid state phase inverters is nothing new. Peavey was doing it decades ago. The 6405MH uses a mosfet PI.
Super intersting thing to try out. One of the problems with just sticking in those fets is that while they work (Somewhat) in the circuit, they have diferent characteristics as far as biasing goes. They generaly will use lower "Cathode" resistor values to be pulling the same current that the tubes pull in the same circuit. You could try rebiasing them to put the plate voltages at the same values that they have with the tubes. THen the main problem would be to reduce the gain - I would suggest using partially unbypassed cathode resistors in order to do this.
You know, I didn't even think to check the numbers, I just yolo bombed them in there. In a future video I package them onto a base so that they can be used properly. Since then, I've tried them in various applications, some they work well, some they don't work at all. It's funny you mention the unbypassed, I find they do not like positions with bypass caps at all, not larger ones at least. As it stands right now, they either work or they don't and there is about one place I have liked it enough that it lives there now, V2 in a Marshall Jubilee. That's that amps FX loop buffer, it actually makes the amp better. If I was building a clone of one today, I wouldn't even bother with that tube position, I'd jsut hard wire in the Fets. I think it makes sense based on what you say, cause those positions have very low Cathode resistors with no caps. 1.5k and 470z.
LND150 needs tweaking It's allmost same curves as a EF86 = pentode... If want the lnd150 to act more as a 12AX7 u need to lower the "grid" resistor on the input/gate... Also U need a DC blocking cap on the input... If the lnd150 fail u will get +150 V dc in your guitar... Also need 18V zeners protecting the gate (max 20V AC)
Oh for sure, I know they aren't implemented correctly. It was just an experiment right. Those are some good notes tho if I did want to go further with these. And I'll admit, I never really knew the reason for a cap at the input of some amps. That makes sense that it's a safety thing. Thanks for that insight.
I love just the first transistor swap sound best as the amp kept its character. Will you put a switchable board in? It would be a lot of work, but not hard and each of the tube\transistor sockets would be fully configurable.
What I ended up doing was making some pop in units out of "socket savers" to sub out tubes when I want to. One of them lives in my Jubilee in the FX buffer position. I'll have a video about it eventually.
I thought the transistor Phase inverter and full transistor pre actually sounded good through the camera. I agree in just the phase inverter position it sounded great, possibly better
More trouble than it's worth. Their claim to fame is that they operate at high tube amp voltages, like 300-500v. Making a pedal that runs off 400v, hah, at the end of the day, they don't "sound" any better than a lower voltage transistor, and many have already crafted pedals using transistors in the same topology as a tube amp.
They have so far been safe in every position I've tried them. Whether they will sound good or not is the question. I have other video where I actually built this into a module. So far one of these modules lives in V2 in my Jubilee clone. And Another is in the Tremolo driver in an old Traynor Custom Reverb head.
@@DATT i too have a clone that i built myself, a 50 watt version of the kerry king 2203. I had thought maybe adding some extra stages for gain, like an slo. It would seem they might be good for the driver and the cathode follower stages. Speaking if the SLO, i think theres a few cathode follower stages, one for the tonestack, and a couple for the effects loop. Might just do that type if circuit justice, having the gain, but using the solid state devices for the followers.
@@KB_Joys Ah yeah, we tried this in the SLO, it worked well in V4 which is the FX buffer stage, half of it is a cathode follower. Didn't really vibe in the other positions. The FX recovert stage in the SLO, unmodded, doesn't have a bypass cap. Once modded with a bypass cap the Mosfets don't work well anymore. That is one thing I found in testing. When properly used, these FET's will have different values on the cathode side than tubes. Without mods, they worked well in tube stages that did not have bypass caps, or if they did, had very little capacitance. If the tube stage had a bypass cap, I think even of just 1uF the FET's didn't sound good. Most amps in there distortion generation stages tend to have bypass caps, so drop in, these FET's didn't sound good in a lot of positions.
@@DATT could build a jcm800 very easily in an amp that only had 2 preamp tubes. Use the mosfet for the cathode follower. I have a jet city jca20h that i always wanted to add another stage in. I could probably be pretty happy doing a slo- ish thing in there. 🤔 I think it might be time to order some parts, lol
@@KB_Joys Marshall did that with the JCM1, maybe you'd find that circuit interesting. It's very very similar to the JCM 800, but they used the FET for the cathode follower, and they used a short tail phase inverter instead of the usual. So they did essentially that, build an 800 with only 2 preamp tubes. If the JCA20 is anything like my JCA50, it doesn't need any more stages. If you want more gain, just change the cold clipper cathode value from a 39k to a 10k, and bam, full shred metal. If it needs more gain than that, I'd say there is either something wrong with it, or it's not the same as the 50. Mind you I also cleaned up the gain in mine a bit by changing the 220k anodes to 100k. Figger is tight af.
Oh snap eh, Yeah I just looked, but of been bit by the chip shortage. Rn, Digikey.ca show a few of one kind in stock. Mouser is dry. I could find schmitt inverters for a while there, they'll be back before you know it.
@@geezberry8889 Really? I'm finding listing for cheaper, but direct from china. Seems there are $15 each listing in Europe. Yeah, might be a lul in the market. But They'll be back.
@@geezberry8889 3 weeks isn't bad to me. In Canada I'm used to slow. Used to be stuff from the states took 3 weeks, stuff from China took 2 months. Things have gotten faster lately. I think "the situation" there caused and increase in demand that caused logistics to upgrade and optimize.
@Do All The Things ! you should contact me, i have a way better way to use this LND150's like that. i never thought to try them raw like that and was impressed they worked so easily. great video
This is a really cool idea. It could be very useful as a diagnostic tool to track down noise, or check for a bad tube in a preamp. I couldn't really tell from the video if the transistor had any appreciable hum or hiss though.
I can't recall off the top of my head, but I think if I had of noticed excess noise, I would of said something in the video.
In practice, they can fill a role. One position in my Jubilee greatly improved the amp overall.
my man i believe you have solved the national tube crisis
Hah, it does work in a pinch, I'd hardly say it works as well as tubes, and unless you craft some way to securely mount the fets in the socket, it could be a bad time.
@@DATT
JetCity Retrovalve. What's old is new,
@@rangerdoc1029 Oh yeah, I've heard of those. There is more too them than just jamming transistors in the sockets.
We need more of these kind of experiments!
I think I have a couple more filmed.
LND150s are the shit. Running them as gain stages at high voltage in pedal designs makes the most dynamic response ever. The reason solid state doesn't sound or feel as good as tubes is because of the low voltages, not because of the sand.
But using solid state phase inverters is nothing new. Peavey was doing it decades ago. The 6405MH uses a mosfet PI.
Yeah they are pretty good for clean buffer applications. I used them to build an effect loops buffer for my Jet City. Way better than the stock one.
22:37 you're right that is a sick tone for doomy sludge
I know right, Gross !
Thats wild, what a great experiment.
I thought it was worth a try. I'm surprised it worked as well as it did.
THANK YOU FOR BRINGING LND150'S INTO MY KNOWLEDGE
Your whole welcome. They aren't a widely practical substitute, but they can work well in some applications.
Super intersting thing to try out. One of the problems with just sticking in those fets is that while they work (Somewhat) in the circuit, they have diferent characteristics as far as biasing goes. They generaly will use lower "Cathode" resistor values to be pulling the same current that the tubes pull in the same circuit. You could try rebiasing them to put the plate voltages at the same values that they have with the tubes. THen the main problem would be to reduce the gain - I would suggest using partially unbypassed cathode resistors in order to do this.
You know, I didn't even think to check the numbers, I just yolo bombed them in there.
In a future video I package them onto a base so that they can be used properly. Since then, I've tried them in various applications, some they work well, some they don't work at all.
It's funny you mention the unbypassed, I find they do not like positions with bypass caps at all, not larger ones at least. As it stands right now, they either work or they don't and there is about one place I have liked it enough that it lives there now, V2 in a Marshall Jubilee. That's that amps FX loop buffer, it actually makes the amp better. If I was building a clone of one today, I wouldn't even bother with that tube position, I'd jsut hard wire in the Fets. I think it makes sense based on what you say, cause those positions have very low Cathode resistors with no caps. 1.5k and 470z.
LND150 needs tweaking
It's allmost same curves as a EF86 = pentode...
If want the lnd150 to act more as a 12AX7 u need to lower the "grid" resistor on the input/gate...
Also U need a DC blocking cap on the input...
If the lnd150 fail u will get +150 V dc in your guitar...
Also need 18V zeners protecting the gate (max 20V AC)
Oh for sure, I know they aren't implemented correctly. It was just an experiment right. Those are some good notes tho if I did want to go further with these.
And I'll admit, I never really knew the reason for a cap at the input of some amps. That makes sense that it's a safety thing. Thanks for that insight.
@@DATT
This is a LND150 "jcm800" preamp
Yes was made about 10 years ago 😊
ruclips.net/video/cB5XaE_vEJk/видео.html
Oh yeah eh? Seems he purpose built a circuit to use the LND. I found his website, that guy has some cool projects. Thanks for the lead.
Yo. My guy. This is gold. What a channel. You hit all the goods.
Thanks !
I love just the first transistor swap sound best as the amp kept its character. Will you put a switchable board in? It would be a lot of work, but not hard and each of the tube\transistor sockets would be fully configurable.
What I ended up doing was making some pop in units out of "socket savers" to sub out tubes when I want to. One of them lives in my Jubilee in the FX buffer position.
I'll have a video about it eventually.
I thought the transistor Phase inverter and full transistor pre actually sounded good through the camera. I agree in just the phase inverter position it sounded great, possibly better
Yeah, some of the effect gets lost in the recording. It does work well in clean buffer positions. These things live in v2 of my Jubilee.
Nice experiments
Thanks!
In sort of reverse to this, I wonder how well you could make a pedal version of a tube preamp with these?
More trouble than it's worth. Their claim to fame is that they operate at high tube amp voltages, like 300-500v.
Making a pedal that runs off 400v, hah, at the end of the day, they don't "sound" any better than a lower voltage transistor, and many have already crafted pedals using transistors in the same topology as a tube amp.
This is aggressively based. I am in awe. Godbless
Aggressively based ? Ah, not sure I understand, is that a good thing ?
Thanks ....i have a new knowledge...
You're Welcome !
Love the videos, love the experiments, bro, but that playing needs a whole lotta work. You sound like the metal TTK 😂😂
Oh yeah, I like to tinker with the gear, but I was never the best player.
Not sure what TTK is.
@@DATT It's the tone king!
Keep it up man, every day js an opportunity for improvement and more tinkering!!
@@JohnWiku Oh, it's another youtube channel. Funny thing is, I don't watch any channels about amps.
Such thing exists / the secret scematic to be like tube .
AMT 12AX7WS Warm Stone LE
I'm familiar with those. It's not the same. Probably better results tho.
Which stage would you say that you could safely replace a tube and has the least amount of difference?
They have so far been safe in every position I've tried them. Whether they will sound good or not is the question. I have other video where I actually built this into a module. So far one of these modules lives in V2 in my Jubilee clone. And Another is in the Tremolo driver in an old Traynor Custom Reverb head.
@@DATT i too have a clone that i built myself, a 50 watt version of the kerry king 2203.
I had thought maybe adding some extra stages for gain, like an slo. It would seem they might be good for the driver and the cathode follower stages.
Speaking if the SLO, i think theres a few cathode follower stages, one for the tonestack, and a couple for the effects loop.
Might just do that type if circuit justice, having the gain, but using the solid state devices for the followers.
@@KB_Joys Ah yeah, we tried this in the SLO, it worked well in V4 which is the FX buffer stage, half of it is a cathode follower.
Didn't really vibe in the other positions. The FX recovert stage in the SLO, unmodded, doesn't have a bypass cap. Once modded with a bypass cap the Mosfets don't work well anymore. That is one thing I found in testing. When properly used, these FET's will have different values on the cathode side than tubes. Without mods, they worked well in tube stages that did not have bypass caps, or if they did, had very little capacitance. If the tube stage had a bypass cap, I think even of just 1uF the FET's didn't sound good. Most amps in there distortion generation stages tend to have bypass caps, so drop in, these FET's didn't sound good in a lot of positions.
@@DATT could build a jcm800 very easily in an amp that only had 2 preamp tubes.
Use the mosfet for the cathode follower.
I have a jet city jca20h that i always wanted to add another stage in.
I could probably be pretty happy doing a slo- ish thing in there. 🤔
I think it might be time to order some parts, lol
@@KB_Joys Marshall did that with the JCM1, maybe you'd find that circuit interesting. It's very very similar to the JCM 800, but they used the FET for the cathode follower, and they used a short tail phase inverter instead of the usual. So they did essentially that, build an 800 with only 2 preamp tubes.
If the JCA20 is anything like my JCA50, it doesn't need any more stages. If you want more gain, just change the cold clipper cathode value from a 39k to a 10k, and bam, full shred metal. If it needs more gain than that, I'd say there is either something wrong with it, or it's not the same as the 50. Mind you I also cleaned up the gain in mine a bit by changing the 220k anodes to 100k. Figger is tight af.
if you're holding a bunch of LND150's you have struck it rich. they're near impossible to find
Oh snap eh, Yeah I just looked, but of been bit by the chip shortage.
Rn, Digikey.ca show a few of one kind in stock. Mouser is dry.
I could find schmitt inverters for a while there, they'll be back before you know it.
@@DATT $15 apiece on ebay smh
@@geezberry8889 Really? I'm finding listing for cheaper, but direct from china.
Seems there are $15 each listing in Europe. Yeah, might be a lul in the market. But They'll be back.
@@DATT i bought from amazon some. they sell 5 for $11 with shipping. from china i assume takes 3 weeks to get.
@@geezberry8889 3 weeks isn't bad to me. In Canada I'm used to slow. Used to be stuff from the states took 3 weeks, stuff from China took 2 months. Things have gotten faster lately. I think "the situation" there caused and increase in demand that caused logistics to upgrade and optimize.
16:32 Sunn O)))
Def could give you a sludgy tone.
@Do All The Things ! you should contact me, i have a way better way to use this LND150's like that. i never thought to try them raw like that and was impressed they worked so easily. great video
Yeah they work, but they could sound better. Do you have a link to a schematic or something ?