Quote from: g1
You posted 2 schematics, look at the other one for masters and reverb.

Ok, I found master and reverb knob thanks.

Quote from: g1
I guess there is a FX level pot also on the back of unit?

Yes, I have effects send/return and knob for effect mix.

I have a few more questions:
1) In the schematic a in the preamp circuit there is C15 but instead of the value is written Ɔ/C what it mean?
2) In the schematic b there are A1 and A2, I must consider them linked together?
3) In the schematic a there is TP1 10V, what is it? where is it connected?
4) In the schematic b, the circtuit on the bottom left with AC IN. What is it? What is it for? What are the components IC4: 7812 and IC5: 7912?
5) In the schematic a/b there is a node called: Boost LD, that comes from input jack RNB - BOOST... But I don't have this jack on the back of the amp (attached the image to this post). Where it should be this input jack? what is it?


Thanks in advance for any replies.

QuoteThe inductance (impedance) ratio looks far too high.

A pair of 6BQ5's in push-pull require 8k plate-to-plate, so a quad requires about 4k p-p, which is 1k either side of the centre tap.

1000/8 = 125:1
125 * 0.3 = 37.5H each side of the primary.

Ok, thanks.

QuoteYou will find a potentiometer symbol and associated sub file at Yahoo Groups LTSpice Group.

I'm sorry I explained badly, I write better the question.
From the schematic I found only 6 knobs:
Channel 1: Gain, Treble, Middle, Bass, Volume
Channel 2/3: Gain, Treble, Middle, Bass, Volume

I hope I identified them correctly. The problem is that I can't find from the schematic this knobs: Reverb, Volume 1 and Volume 2.

Here are pictures of the amplifier and knobs shown on the schematic:
https://www.dropbox.com/s/9xidsnorwh3o8pg/peacemaker%2040%20images.pdf?dl=0

Thanks in advance for any replies.

Quote from: teemuk
There are several options to overcome the particular issue:

Yes thanks, my bad. Obviously with an high frequency input signal the simulation integration step must be much smaller.
So, I've done a simulation of 20 seconds by placing the input to 0V and then I took the voltage values. I used the command ".ic v (node) = value" to set initial condition, in orther to get faster the steady state.

Here the new version of the spice schematic:
https://www.dropbox.com/s/r9xfff70h5t39b9/peacemaker%2040%20spice.png?dl=0

I also understood how to connect the CT voltage. Reguarding the inductance values, I took them from another schematic, but I don't think they are also suitable for this circuit.
1) How can I get the correct values for this amplifier?

The final output signal is near to be a square wave, I think it's too distorted to be a clean channel.
2) Where I can find in the schematic, the potentiometer for power amp volume?

In addition, the value of CT fluctuate, more less, between 342V and 300V.
3) It's normal, or it's too much?


Thanks in advance for any replies.

Tnx, for the answare. I have a few more questions.

Quote from: g1
The belton tank is the equivalent of an accutronics model 8EA1C1B.

On the accutronics website I only found the 8EA2C1B, it's the same?

Quote from: Roly
Unless you want to get neck deep, as a simple transformer represented by the resistance and inductance of the line driver and receiver, where you will get signal but no reverb delay. {If you really want to simulate a reverb springline then you will need to model it as a transmission line, but there is seldom any need to go to those lengths.}

For the moment I'm only interested in simulating its behavior when the reverb knob is at 0. It's just a impedance? Or there are also some non-linearity or other behaviors to be simulated?


At the moment I realized the circuit on spice bypassing the reverb/effects part and I used this transformer model:

.SUBCKT OutXFMR_10k:8 1 2 3 4
L1 1 5 200H
R1 5 2300
L2 3 6 .16H
4 .2 6 R2
K1 L1 L2 .99996
C1 1 5p 5
C2 3 6 20p
C3 5 6 200p
.ENDS

I don't know what should be the input impedance. So the 10k value was chosen randomly.

Since I am not practical, I would like to know if there are any errors in the circuit that I wrote. Surely the CT voltage is placed in the wrong way, but I haven't understood how to place it.

Here the images from spice circuit:
https://www.dropbox.com/s/6ul6o3s4crgm9jd/peacemaker%2040%20spice.pdf?dl=0

Regarding the power supply circuit, I'm having trouble in transient simulation since the CT, G2, HT1, HT2, HT3 voltages take a long time to get up to steady state and the simulation time become too long.
I would like to replace these volteges with ideal generators, but first I need to know the right value, how can I do this?

Thanks in advance for any replies.

Hello,
I have some doubt about the schematic of this amplifier, I attach the file.

My purpose is not to physically build this amp (since I have the original at home). I'm studying about amp modeling, so I want to simulate it.
First of all I need to copy the amp schematic on spice, in order to make a comparison between the model and the real amp.

So, these are my questions:

1)
First of all, I want to ask about power supply circuit that generate DC voltage for the tube.
It is placed in file b in the bottom right.
Blue-1 and Blue-2 represent the power socket right?
I have a doubt about the inscription "AC IN 270", what is 270? It's the effective value or the peak value?

However, I implemented this circuit in spice using 50Hz 270V sine input, in other to find CT, G2, HT1, HT2 and HT3. The problem is that I get the same DC output voltage for each of them, I don't think that this is the correct result, what do you think about that?

2)
The second question is about the Belton Reverb always located in the file b. I think it is a spring reverb, but how can I model it on spice? in other searching on google that brand/model did not find any results.

3)
The last question is about ouput transformer, it can be found in file a. I don't fully understand the meaning of the "ring symbol" for which a color is indicated (ex. BLUE YELL WHITE BLACK ecc), what do they represent?.
In addition to model accurately the transformer I should know the brand/model in other to know the material and the non-linear relationships.
From this schematic how can I know what type of transformer is that? how can I get its model?
Since that I have the physical amplifier at home maybe I can see the model dismounting it?

Thanks in advance for any replies.