Intact Audio

Yes, I did look at the mix. Because of the characteristics of each, you can use a mix to compensate things. As Dave reported, one thing that is possible is to linearize the inductance with respect to signal level and/or frequency. Thew downside, as Dave also pointed out is the saturation characteris...

Thanks Lars,
Whenever someone posts another part, I'll typically cut and paste it into my LTSpice file. Over time things tend to grow nicely that way.

The most recent things I added was a bunch of varactor diodes, and a few RF transistors.


Stephie <3

They are collected from a bunch of sources. I made some, others made some.
They are in the "sticky" section in the "sim city" section

Stephie <3

I have updated the triode_nh.txt and the tetrode.txt files to include both the triode and pentode sections of the 6BL8/ECF80. They are in the sticky part of this section.

Nice to see you, Christian.

Hugs,
Stephie <3

I have added the triode and the pentode sections of 6BL8/ECF80 to the files. Both triode_nh.txt and tetrode.txt have been modified and are attached. In this version of tetrode are 2E24, 6AC7, 6AK6, 6AN8, 6AQ5, 6AU6, 6BH6, 6BL8, 6BM8, 6BQ5/EL84, 6CA7/EL34, 6E5P, 6KG6/EL509, 6L6, 6L6GC, 6SJ7, 6V6, 12B...

Both changes... removing R2 or bypassing to the supply rather than ground affect power supply induced noise, but neither affect the increase in tube noise caused by the addition of the input cathode follower. If you're limited by hum buzz etc, that sometimes helps a lot... if you're limited by raw t...

Just redid some of the sims with higher impedance OPT. For 80+80H to 200mH (12.8k to 8 ohm) the circuit remains essentially A1 or A2 never hitting class B. The clip point is slightly over 25 watts. At 25 watts the distortion is 3%, at 30 watts (into clip) it is 6.5%. Transition between A1 and A2 is ...

Hi, In your circuit, if you turn around the secondary (L2), you can add a little bass boost by a voltage divider at "U2" grid and the 3k resistor between the 2 chokes. For instance changing that 3k into a 2.9k and 51 ohm resistor and connect the tap to the grid of U2, you get a 2.5dB boost...

Should work reasonably well. The cathode follower input stage will indeed keep capacitance down, but this is never the lowest noise configuration. If it's quiet enough for you, it will have the other characteristics you are looking for..... Still, I'd worry about the noise.

Stephie <3

Hey Dave and all, Got busy, so haven't been on the forum for a bit. This girl has several things happening.... On the higher impedance... The amp will stay in Class A / A2 over a longer range, and the power output will be just a tad lower, but will work well. If you look at the distortion plot way a...

In pentode mode 6E5P 3.5 volt bias. I changed the resistance of L1 to 3.32k. This puts the grid of the GU81 at -89 volts. 6E5P total current =27mA, 5 watts (23+4mA) Gu81 at 1600v, 267mA=450 watts. Changed primary ind to 130H, 1 ohm load from 32.5mH. 2v peak in produces equal 2nd and 3rd harmonics at...

That might make it more linear, I'm seeing a couple hundred watts even in pentode mode before things get too out of hand. I adjusted biasing slightly on your circuit. Do a DC analysis first, before the transient analysis. The way to run UL on this tube is implemented most straightforward using an ad...

The Spice file below (tube_build.asc) is intended to allow you to more easily create a Spice model for a triode. You can adjust the tube parameters in the model, and run the simulation to see if they correctly model your device. The adjust parameters are a superset of the Koren and the Java Script p...

The attached file is the updated triode_nh.txt file. I have added a new generic device called build_triode. This was added as it goes with another file that I'll put in a different thread in this section called tube_build.asc. This allows you to relatively easily build your own device and take the g...

Notice the odd order distortion (3rd) is showing the clipping that your waveform is also showing. Back off a little on the drive to see what the structure out of clip is. If you're driving at 2 volts, back off to about 1.5 volts (slightly less than 3 dB) and look at the harmonic structure. It will g...

I was planning to send a spice file with build-your-own-triode with things set up for you to tweak things, then simply update your triode_nh.txt file to include the tube... should look something like the attached.

Does this seem useful?

Stephie <3

For FFT to be reasonably accurate, you have to have a LOT of cycles. If you're simulating 1kHz for instance, run the simulation for 500ms or so so it accumulates many cycles. (in this example, it would be 500 cycles of 1kHz)

Enjoy,
Stephie

Drop down menu for tetrode.txt with the GU81M has been placed in the "sticky" folder. It's reasonable for both A1 and A2 operation. Optimum with 500 volts on G2, but relatively OK. Fair to middlin in triode mode.

Should be useful for electrocution purposes.

Enjoy,

Stephie <3

I have added GU81M to the tetrode drop downs. Reasonably accurate in A1 and A2 modes. The following are in the drop down... 2E24, 6AC7, 6AK6, 6AN8, 6AQ5, 6AU6, 6BH6, 6BM8, 6BQ5/EL84, 6CA7/EL34, 6E5P, 6KG6/EL509, 6L6, 6L6GC, 6SJ7, 6V6, 12BY7, 12GN7, 807, 813, 6146, 6550, 6688/E180F, 7754/7695, 7721/D...

I thought you would use it pentode mode. Should have a model available in a few days.

Stephie <3

Been Busy at work. I'll see what I can do. I did download the datasheet. 12.6V 11A filament, it should be nice and bright. Low gi-g2, so triode connection, although not particularly linear, would be low plate resistance.

Stephie <3

Hi folks, As I mentioned in the other string, there are a lot of tubes (72) in the current compilation using several different models. The two most popular models are the generic triodenh, which I think, started with Dave Cigna, and the voltage/current model which started with Norman Koren. I've mod...

833A is a spectacular device with which to perform that operation. :D Only certain of the devices in the "library" support A2 (811, 801 come to mind) in a realiatic way, although I've added some level of grid current support to most models (but not all). Most of those, except for ones that...

Here's the latest triode no heater drop down. Devices available... 01A, 2A3, 2A3_sofia, 2C51, 3A5, 3CX300, 6AM4, 6AN8T, 6AS7_6080, 4x6AS7_6080, 6AQ8, 6MB8, 6BQ5_EL84, 6C33_sofia, 6C4C, 6C45-PE, 6CG7, 6CW4, 6DJ8, 6H30, 6HV5, 6J4, 6J6, 6N1P, 6N6P, 6SL7GT, 6SN7GT, 6SN7_sofia, 12A4, 12AT7_ECC81, 12AU7_E...

I'll add one into the triode_nh.txt "drop down" files. It models anode and grid currents reasonably well. I'll attach a .PDF to this reply that gives the differences between the tube data and what I was able to achieve.

Stephie <3

Not a problem, I embarassed myself there for a while. Can't describe how much better I am now though. EL34 is a pretty nice critter, and nice equally in triode mode. Tetrodes in triode offer some interesting options, since you can make the triode connection via a resistor, and that leads to some int...

Gosh! are you folks gonna make me do another run of boards? I'll have to resurrect that layout. IIRC, there was a mistake in the layout that I'll correct.

Haven't looked at it in years now.

Stephie <3

While you have the standard library files open... one thing that comes in very handy is an "ideal" diode). This critter immediately conducts at 0 volts and has low resistance (I used 1 milliohm). Feel free to add it into your .DIO files. Also I usually put the tube diodes and VR tubes (as ...

The attached tetrode.txt contains the following devices 2E24, 6AC7, 6AK6, 6AN8, 6AQ5, 6AU6, 6BH6, 6BM8, 6BQ5/EL84, 6CA7/EL34, 6E5P, 6KG6/EL509, 6L6, 6L6GC, 6SJ7, 6V6, 12BY7, 12GN7, 807, 813, 6146, 6550, 6688/E180F, 7754/7695, 7721/D3a, 7722/E280F, 7788/E810F, D3a (different model), EF86, KT88, SV83....

If you open those files .mos, .dio etc under LTSpice, it will correctly save the extension. One of the tricks I use is to put my name or some other identifier in the "manufacturer" field so I know they are "additions" to the file. On 6688, I'll try to do that one soon and update ...