Search found 61 matches

by jarek
Sat Sep 22, 2012 11:21 pm
Forum: Sim City
Topic: 842 Triode Spice
Replies: 7
Views: 6086

Stephie, I've realized the tube was in some strange operating point as I entered it in the design. Once I've corrected the OP, it has started to work ok :)
by jarek
Fri Sep 21, 2012 4:34 pm
Forum: Sim City
Topic: 842 Triode Spice
Replies: 7
Views: 6086

OK, it has started to work. No idea what was wrong, but it works now :-)
Thanks again Stephie!
by jarek
Thu Sep 20, 2012 10:27 pm
Forum: Sim City
Topic: 842 Triode Spice
Replies: 7
Views: 6086

Heey Stephie! Thank you very much! Unfortunately trying to simulate I get a "Timestep too small" error. Never had it with other models. Wondering why... PS Apparently the trouble is indicated with 6E5P tube, which so far has been working 100% ok with other models from triode_nh (801A, 2A3,...
by jarek
Thu Sep 13, 2012 6:22 pm
Forum: Sim City
Topic: 842 Triode Spice
Replies: 7
Views: 6086

842 Triode Spice

Hi all! I came across a very interestingly looking triode
from the 800-family: 842
*Moderate Ra @ 2.5k
*12W dissipation (or more if someone wants steroid KR tube version)

..anyone has a Spice model? The usual suspect Stephie ;)?

Thanks!
-j
by jarek
Thu Sep 06, 2012 12:00 am
Forum: Phono
Topic: Switching of the phono inputs
Replies: 11
Views: 12120

Finally, after some crawling through the hughe Blowtoch thread on diyaudio.com:

http://www.diyaudio.com/forums/solid-st ... -1570.html

I'll experiment with a big shallco switch from nebraska surplus:

http://www.surplussales.com/Switches/SWRotaryAll-1.html
by jarek
Mon Sep 03, 2012 11:41 am
Forum: Phono
Topic: Switching of the phono inputs
Replies: 11
Views: 12120

Continuing my search, I came across TKD 2R6A switch: http://www.tkd-corp.com/pdf/p05_2r6a.pdf Solid silver, less than 5mOhm resistance (for comparison Hg-wetted relays are about 50mOhm), fully enclosed...not bad! ...and whooping 200Eu + shipping/pcs :O Which actually given the price of Hg-wetted rel...
by jarek
Fri Aug 31, 2012 1:45 pm
Forum: Phono
Topic: Switching of the phono inputs
Replies: 11
Views: 12120

I've found a detailed pic of the EMT JPA-66 innards http://audio16.wordpress.com/tag/emt-jpa-66/ It seems there are using Takamisawa A12W-K relays for switching (also I guess the signal: the relays below SUT's seem the same) Golden contacts--ok, 50mR but at 1A, ...ok but not imressive. No ida if the...
by jarek
Tue Aug 28, 2012 10:35 pm
Forum: Phono
Topic: Heaters for Phono stages - questions.
Replies: 5
Views: 8109

I pre-het the tubes for 2mins before switching the HT. This is done with a time realy in HT PS transformer primary: the relay is driven by the heater voltage, taken at the firs LC cell. What I have recently observed is that the heater voltage drops a bit after switching of the HT supply on: from 13....
by jarek
Tue Aug 28, 2012 9:28 pm
Forum: Phono
Topic: Switching of the phono inputs
Replies: 11
Views: 12120

Here is one more specimen:

http://www.torontosurplus.com/midland-r ... 00014.html

Interesting that it's supposedly latching...but getting any datasheet seems impossible
by jarek
Tue Aug 28, 2012 6:44 pm
Forum: Phono
Topic: Switching of the phono inputs
Replies: 11
Views: 12120

Is it not possible to find a few examples of these relays NOS or loan from others, to test, instead of spending big bucks ? I'm trying, with little success so far--neither Rhopoint nor few other replied. I understand that Hg-wtted would be hard to get in EU due to some idiotic fantasies of EU burea...
by jarek
Mon Aug 27, 2012 6:29 pm
Forum: Phono
Topic: Switching of the phono inputs
Replies: 11
Views: 12120

Thank you Island! This is just an idea, which may as well be a no-go. Everything depends on how much I get quoted for those toys to be able to experiment. I got a quote for 50GB5N...630$/pcs (!!!!)...maybe ok for a Gulfstream Jet, but I recon too much even for an Allnic H3000...speaking of the later...
by jarek
Mon Aug 27, 2012 1:51 pm
Forum: Phono
Topic: Switching of the phono inputs
Replies: 11
Views: 12120

There is also this military toy: 50GB5N-1-A700 which I've found through diyaudio: http://www.jogis-roehrenbude.de/Verstaerker/6C33C-VV.htm Hard to get any reasonable datasheet, not written in the military language. There is a whle family 5GB5N. It seems to be hermetical, Hg-wetted and not a reed: th...
by jarek
Sun Aug 26, 2012 3:07 pm
Forum: Phono
Topic: Switching of the phono inputs
Replies: 11
Views: 12120

Thanks Dave! I've never seen anything more advanced than a mechanical switch at the phono input. If anyone has any experience with thermocouple relays, I'd be interested to learn. I've contacted Rhopoint, since Hg-wet are not standard. Let's see what they quote... BTW, how do you guys deal with mult...
by jarek
Sun Aug 26, 2012 10:44 am
Forum: Phono
Topic: Switching of the phono inputs
Replies: 11
Views: 12120

Switching of the phono inputs

Hi all! I don't know if the topic has already been discussed (if so apologies for not searching hard enough :): how to switch phono inputs? For some time I've been chewing on the idea of using Hg-wetted thermocouple reed relays. They are supposed to be designed for switching microvolt signals, gener...
by jarek
Sun Aug 26, 2012 10:19 am
Forum: Phono
Topic: Heaters for Phono stages - questions.
Replies: 5
Views: 8109

Andy, in my heavy Pussy EAR834 clone, I use a huge choke input (0.3H/1A) supply with SiC diodes, followed by another LC cell, then RC and finally LT317A-based CCS for each individual tube, decoupled with a tiny wima plastic cap at the socket. The supply is overblown perhaps for heaters, but the same...
by jarek
Sat May 14, 2011 8:37 pm
Forum: Sim City
Topic: GU81M
Replies: 17
Views: 26489

I must be a complete Spice idiot as the mentioned by Stephie configuration gives me only this:
by jarek
Sat May 14, 2011 1:11 am
Forum: Sim City
Topic: GU81M
Replies: 17
Views: 26489

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 a...
by jarek
Fri May 13, 2011 3:28 pm
Forum: Sim City
Topic: GU81M
Replies: 17
Views: 26489

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) Hmmm...my motivation was that in the triode mode, run hard to eventually supply a bit of a grid current, 6E5P would give a more linear...
by jarek
Fri May 13, 2011 2:05 pm
Forum: Sim City
Topic: GU81M
Replies: 17
Views: 26489

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. Hmm...I thought I've done it. What operating point do you get? And what load?...
by jarek
Fri May 13, 2011 11:14 am
Forum: Sim City
Topic: GU81M
Replies: 17
Views: 26489

Ultralinear?

I'm wondering if there would be a way to put into the ultralinear mode?
The problem is 1kV difference between the G2 and the plate...

Cheers,
jarek
by jarek
Mon May 09, 2011 6:34 pm
Forum: Sim City
Topic: GU81M
Replies: 17
Views: 26489

It seems that it just wants to clip...the bias was always negative but the cut-off is ugly. I've followed your instructions, below is the FFT for 20Hz @ 1.4Vrms with 2x less load set at 2k. It gives only 90+W, which makes it unattractive as big triodes like 833 can do that too. And without so much d...
by jarek
Sun May 08, 2011 12:28 am
Forum: Sim City
Topic: GU81M
Replies: 17
Views: 26489

me idiot :oops: thank you Stephie!

Below are the plots for more cycles. Stephie, form your experience, how to interpret them? To me looks like guitar amp, but i have no experience.

what are the dips right before some harmonics?

thank you!
jarek
by jarek
Sat May 07, 2011 5:38 pm
Forum: Sim City
Topic: GU81M
Replies: 17
Views: 26489

There is a discussion on Romy's site about a powerfull >100W SET amp to drive a dedicated bass channel 50-100Hz max. Romy has imposed a series of constraints, e.g.: 2 stage design, no IT coupling, no parallel drivers, no cathode followers, pref. DC coupled, etc etc. Since I have some heavy HV iron I...
by jarek
Wed May 04, 2011 9:32 pm
Forum: Sim City
Topic: GU81M
Replies: 17
Views: 26489

Thank you Stephie!!!!
Let's see how linear this electrocution is ;-)
I don't want to be electrocuted by a distorting , non-linear
chair :evil:
I'm also trying to see if a triode connected 6E5P DC cpoupled will drive it (<100Hz)...

Cheers,
jarek
by jarek
Sat Apr 23, 2011 1:00 pm
Forum: Sim City
Topic: GU81M
Replies: 17
Views: 26489

Stephie, I was thinking of it in a pentode mode rather, G2 can handle only 600V max. The goal is a powerfull, 150W+ single ended electric chair...eeee....bass amplifier. The point I was looking at is 1500V/300mA 3.2k load. Would be interesting to see how non-linear it is and how it matters given the...
by jarek
Wed Apr 20, 2011 11:36 pm
Forum: Sim City
Topic: GU81M
Replies: 17
Views: 26489

GU81M

I've figured out 833A would be to weak to electro-cute well enough, even in A2, but GU81M, pentode mode, should do the job. Anyone (Stephie :):):)?) would have a model: A1 + the onset of A2, G1 and G2, G2 at 500V I've tried contacting this Italiano: http://www.diegobarone.it/ModelloGU81.htm but to n...
by jarek
Sat Apr 09, 2011 3:56 am
Forum: Sim City
Topic: 833A model
Replies: 3
Views: 4620

Stephie, thank you very much! I think I want to kill myself in a spectacular way with 833 :S
by jarek
Thu Mar 31, 2011 1:43 pm
Forum: Sim City
Topic: 833A model
Replies: 3
Views: 4620

833A model

Ok, that's serious---does anybody have a spice model for 833A,
correctly reproducing both A1 and A2 curves?
Thanks!
jk
by jarek
Thu Mar 31, 2011 1:40 pm
Forum: Phono
Topic: BIG nano core SUT challenge
Replies: 2
Views: 5421

Ok, was very surprised not to get any reply, perhaps I've knocked a wrong door...finally Pieter took the challenge.

Cheers,
jk
by jarek
Wed Mar 09, 2011 4:06 pm
Forum: Sim City
Topic: 6336B model
Replies: 6
Views: 6985

Ooops! My apologies Stephie, had no idea :oops:

Steve, once again thanks for the model but I've abandoned this tube,
in favour of a simple EL34, so could not check your model in the real life :(

best,
jarek