PSpice simulation

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Hi everyone,
I'm trying to do a simulation of Bassman 5F6-A (1959) in PSpice. How can I simulate the output transformer? Use magnetic.lib from spice or create a new model? I don't know the core material to use magnetic.lib.

Anyone help me?


fender_bassman_5f6a.gif
 
Universal Transformer Model.
This has Ultralinear Taps but just connect them to 0V via say 10Meg resistors for simulating the Bassman otherwise the simulator will have a "dummy spit". (Dummy is Oz vernacular for a babies pacifier).

**************************************
*
* Center Tap Audio Transformer,
* for push-pull tube operation,
* with screen grid taps
*
* TransPPSGT
*
* Primary Terminals
* P1, P2 plate connections
* Sg1, Sg2 screen grid connections
* B primary center tap (+Vpp)
* Secondary terminals
* Sp1, Sp2 speaker connections
*
*
* Parameters :
* RP one half primary winding resistance
* LA one half primary winding inductance
* LP one half primary inductance, plate to screen tap
* LS one half primary inductance, screen tap to center tap
* RA impedance ratio, primary plate-plate to secondary
* RS secondary winding resistance
*
* the parameters are related to frequency response as follows :
* let Rs = source resistance ( ie the load at the seen by the plate )
* let RL = load resistance ( ie the speaker )
* then RA = Rs/RL =n^2, where n is turns ratio, Ts/Tp
* let r1 = total primary winding resistance
* let r2 = total secondary winding resistance
* let F1 = upper 3dB frequency
* let F2 = lower 3dB frequency
* if 3dB points are not known, but 1 dB points are, then
* let F1' = upper 1dB frequency,
* let F2' = lower 1dB frequency
* then F1 = F1' x 2
* F2 = F2' / 2
*
* then calculate total series inductance La
* La = (Rs + r1 + (n^2)( RL + r2))/( 2 x pi x F1 )
*
* then calculate total parallel inductance Lb
* Lb = (Rs +r1)(RL + r2) (n^2)/((Rs + r1 +(n^2)(RL +r2))x 2 x pi x F2)
*
* then divide up La and Lb into the multiple windings required
* let t be the screen grid tap percentage,
* ie for a 40% screen grid tap, t = 0.40
* then the parameters are
* RP = r1 / 2
* RS = r2 (NOTE : RS is NOT Rs !!)
* LP = (1-t)Lb/2
* LS = t x Lb/2
* LA = La/2
*
* the default parameter values given are for an 8K to 8ohm transformer,
* with 40% screen grid taps,
* and 30 to 30KHz frequency response (15 to 60KHz 3dB response)
*
.SUBCKT TransPPSGT P1 Sg1 B Sg2 P2 Sp1 Sp2
* PARAMS: RP=25 LA=0.02234801 LP=13.3822388 LS=8.921493 RA=1000 RS=0.8
*
* primary
*
RP1 P1 1 {RP}
La1 1 2 {LA}
LP1 2 3 {LP}
LS1 4 5 {LS}
LS2 6 7 {LS}
LP2 8 9 {LP}
La2 9 10 {LA}
RP2 10 P2 {RP}
RP3 3 Sg1 1
RP4 Sg1 4 1
RP5 5 B 1
RP6 B 6 1
RP7 7 Sg2 1
RP8 Sg2 8 1

*
* secondary
*
Rs Sp1 11 {RS}
LSA 11 Sp2 {8*(LP +LS)/RA}

*
* coupling
*
Kcore1 LP1 LS1 .999999
Kcore2 LP1 LS2 .999999
Kcore3 LP1 LP2 .999999
Kcore4 LP1 LSA .999999
Kcore5 LS1 LS2 .999999
Kcore6 LS1 LP2 .999999
Kcore7 LS1 LSA .999999
Kcore8 LS2 LP2 .999999
Kcore9 LS2 LSA .999999
Kcore10 LP2 LSA .99999
.ENDS TransPPSGT


You should be able to modify this easily to suit the Bassman (or anything else).
Also have a look in the Vaccuum Tube Spice models sticky at the top to see if anyone has put output tranny models in there.

Cheers,
Ian
 
Last edited:
diyAudio Moderator
Joined 2008
Paid Member
For a quick fix you could use an L//R.

Gingertube.. Do you know if this would fit into circuitmaker? Oh, and is Huey active on your side of the stump? There's no let up here, may try to hit up my car insurance for a spray job.
 
For a quick fix you could use an L//R.

Gingertube.. Do you know if this would fit into circuitmaker? Oh, and is Huey active on your side of the stump? There's no let up here, may try to hit up my car insurance for a spray job.

Not at all familiar with Circuitmaker. Have used the simulator which is part of the Altium Designer package but for day to day stuff I use this:
http://www.beigebag.com/
It has quite a few tube models "built in" and is the source of the above transformer model.

Cheers,
Ian
 
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