Fascinating. Glad you found it and well done for proving it with the cutout, and for posting it. We've found similar results but not followed through to prove it so thanks.
We've used material like Tufnol for non-conductive safety enclosures.
Search found 747 matches
- Sat Jul 31, 2021 8:44 am
- Forum: Everyones Projects
- Topic: Poundland 45
- Replies: 160
- Views: 34875
- Tue Jul 27, 2021 7:27 pm
- Forum: Valves
- Topic: D3a Triode Square Wave shows HF boost
- Replies: 17
- Views: 14190
Re: D3a Triode Square Wave shows HF boost
- Mon Jul 26, 2021 9:32 pm
- Forum: Valves
- Topic: D3a Triode Square Wave shows HF boost
- Replies: 17
- Views: 14190
Re: D3a Triode Square Wave shows HF boost
I think Mike (and me) meant the DC blocking capacitor stopping DC from showing a horizontal line instead of calibrating for input capacitance. If you used a 10kHz square, the flat top would not be so affected by the blocking cap. Ok I see ... But there wasn't a blocking cap in the test circuit, eit...
- Mon Jul 26, 2021 2:55 pm
- Forum: Valves
- Topic: D3a Triode Square Wave shows HF boost
- Replies: 17
- Views: 14190
- Sun Jul 25, 2021 3:24 pm
- Forum: Valves
- Topic: D3a Triode Square Wave shows HF boost
- Replies: 17
- Views: 14190
- Sat Jul 24, 2021 12:02 pm
- Forum: Valves
- Topic: D3a Triode Square Wave shows HF boost
- Replies: 17
- Views: 14190
Re: D3a Triode Square Wave shows HF boost
Ok my previous post prompted me to hook up the Siglent.
Looks better. The square wave is still coming from the Picoscope.
Looks better. The square wave is still coming from the Picoscope.
- Sat Jul 24, 2021 11:50 am
- Forum: Valves
- Topic: D3a Triode Square Wave shows HF boost
- Replies: 17
- Views: 14190
Re: D3a Triode Square Wave shows HF boost
I would measure with a sine wave sweep to see if there is a HF boost that you need to worry about. Also, 100nv is 30dB more than it will normally see, do you see the same effect with 1mv input? Thanks Nick I'll report back tomorrow. I've reconstructed the test build so I can get directly to the pin...
- Sat Jul 24, 2021 11:41 am
- Forum: Valves
- Topic: D3a Triode Square Wave shows HF boost
- Replies: 17
- Views: 14190
Re: D3a Triode Square Wave shows HF boost
I thought a droop on the top of a square wave was LF rolloff not HF boost? I'm not seeing HF overshoot. Or am I missing something here? Many use the d3a as input and driver in a power amp so that could see a 1V input. 10K anode load and 1.5V bias should be fine for HT around 300V I'm not understand...
- Fri Jul 23, 2021 10:44 pm
- Forum: Valves
- Topic: D3a Triode Square Wave shows HF boost
- Replies: 17
- Views: 14190
- Fri Jul 23, 2021 9:19 pm
- Forum: Valves
- Topic: D3a Triode Square Wave shows HF boost
- Replies: 17
- Views: 14190
D3a Triode Square Wave shows HF boost
After spending way too much time and effort with work I finally got back to making progress on the phono. I'm starting with a real simple D3a Triode stage and want to get the output from that as clean as I can get it before I start experimenting with what comes after. I've set up the D3a as follows,...
- Wed Jul 21, 2021 8:48 am
- Forum: Everyones Projects
- Topic: Question re Izzy Wizzy phono stage
- Replies: 18
- Views: 6073
Re: Question re Izzy Wizzy phono stage
Many thanksizzy wizzy wrote: ↑Wed Jul 21, 2021 8:41 am Here it is. It's a bit of a mess but seems to work fine.
My LTSPICE is setup like the Tutorials on Intact Audio with the files by Stephie Bench so uses drop down tube models. I'm not sure this will work with LTSPICE using the regular models.
Make sure you have the latest version.
- Wed Jul 21, 2021 7:51 am
- Forum: Everyones Projects
- Topic: Question re Izzy Wizzy phono stage
- Replies: 18
- Views: 6073
Re: Question re Izzy Wizzy phono stage
Well the circuit I am looking at is your current phono from the website. D3a pentode DC coupled via single stage RIAA into 5687 LTP into LL1660.izzy wizzy wrote: ↑Tue Jul 20, 2021 11:00 pm Sure. You'll have to tell what exact circuit you want as I have so many variations even from the latest shown on my site.
- Tue Jul 20, 2021 2:00 pm
- Forum: Everyones Projects
- Topic: Question re Izzy Wizzy phono stage
- Replies: 18
- Views: 6073
Re: Question re Izzy Wizzy phono stage
Actually do you have a file you could send me for your circuit? I have LTSpice and have done a couple of things but wouldn't know how to use the D3a or 5687 models...izzy wizzy wrote: ↑Sun Jul 04, 2021 12:50 pm If you need help with the sim to choose EQ values, happy to help. Will be interested to see what direction you take.
- Sun Jul 18, 2021 9:23 pm
- Forum: Everyones Projects
- Topic: DHT Heater using VCCS - PCB or Kit (Possible Group buy)
- Replies: 1182
- Views: 413491
- Sun Jul 18, 2021 8:13 am
- Forum: Everyones Projects
- Topic: Passive RIAA - single Vs double stage
- Replies: 4
- Views: 1724
Re: Passive RIAA - single Vs double stage
Ok I going to build the PSU and a prototyping amp with the valves and RIAA on interchangable turret boards. HM-3 inputs one end, HT & GND and valve heater connections along one edge, outputs to LL1660 other end. One per channel. I should be able to prototype and swap in different amp modules to ...