Thanks for help, about tube AZ1 rectification wich Tx volts & watts I need to feed SSHV, I suppose that I don't need the chokes & caps for tube rectification or I have to ommit at the SSHV the psu caps, I am a little bit confused about this?
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Who knows where to buy the LL1660 cheaper than in K&K Audio at 115$00 USD each
K & K Audio - Lundahl Transformers, audio DIY kits and more
K & K Audio - Lundahl Transformers, audio DIY kits and more
you can have a look at ★ J A C - M U S I C ★ EMISSION LABS TUBES ★ YAMAMOTO SOUNDCRAFT ★ NOS TUBES ★ You must like:, as he is in Germany and sells Lundahl stuf.
Sorry I have a doubt LL1660PP only can be configured Alt M or Alt N, for Alt Q must be LL1660/18mA SE Line Output😕
I think $115 from K&K may be a good price right now with the dollar exchange. Try JAC Music - my memory tells me that's a bit more expensive. There are dealers in Netherlands and Germany for this, and Canford in the UK as well - LUNDAHL ANALOGUE AUDIO TRANSFORMERS though it's not in stock.
Didn't see the prices of Jacmusic, so I didn't know they were more expensive. Just be aware that shipping from the US is probably going to cost more, and at least for the Netherlans (but theoretically all European countries) you will have to pay the local VAT and possibly some handling/administration costs by the local customs (I am assuming you are in Spain).
I have not followed this thread, but I understand you are looking for a 4,5:1 ratio (Alt Q connection in the LL1660 datasheet), so you can possibly also use the LL1680, which is designed for 5mA current (and 210H) and can also be configured as 4,5:1.
http://www.lundahl.se/pdfs/datash/1680.pdf
I have not followed this thread, but I understand you are looking for a 4,5:1 ratio (Alt Q connection in the LL1660 datasheet), so you can possibly also use the LL1680, which is designed for 5mA current (and 210H) and can also be configured as 4,5:1.
http://www.lundahl.se/pdfs/datash/1680.pdf
Depending on usage you can connect in any configuration you want.
I would suggest to make it first with a plate resistor and cap output.
Hello all,
I have now almost sourced all the parts for my #26 preamp project. The signal part will be plain with Hashimoto 20K line output transformer. The filament will be regulated with Rod Colemans DHT heater. HT will be LCLCLC. It will be a spilt chassis design, one for signal, one for PS.
Before I make a conclusion on the size of the chassis, I need some advice from you guys🙂
Where would you suggest that I spilt the PS? For filament, I was thinking of putting only the regulator board in the signal chassis. And for HT, I was thinking of putting the last LC in the signal chassis.
What do you think?
Theo
I have now almost sourced all the parts for my #26 preamp project. The signal part will be plain with Hashimoto 20K line output transformer. The filament will be regulated with Rod Colemans DHT heater. HT will be LCLCLC. It will be a spilt chassis design, one for signal, one for PS.
Before I make a conclusion on the size of the chassis, I need some advice from you guys🙂
Where would you suggest that I spilt the PS? For filament, I was thinking of putting only the regulator board in the signal chassis. And for HT, I was thinking of putting the last LC in the signal chassis.
What do you think?
Theo
I like keeping all iron (transformers and inductors) away from the signal tubes. So I would split the power supply so that only the last C is in the preamp. And I always like to have some C on both ends of the cable connecting the power supply to the preamp. So I'd put something like a 0.1uf after the last L in the power supply and then put the bigger C in the preamp.
---Gary
I totally agree.
VGeorge, would you be so kind to describe in detail you PS arrangement?
5AR4GU then LCLC (ll1673-47uf-ll1673-200uf) are at the PS case and two SSHV at the pre case. Thinking either move the big cap the pre or put two small caps (0.1uf?) near the regulators.
Heaters supply 15000uf x 2 per channel on the PS box and a 1000 uf at the pre near the regulators.
Theo, Keeping the Filament trafo away from the signal tubes & wiring definitely makes sense. But, be sure to keep the rectifier and capacitors close to the trafo - don't use long wires for these, or they will 'transmit' to other circuits! For a 1A regulator, the rectifier-cap CURRENT pulses may be 5A, with fast rise time. Using the names in my application note AN-DHT01 for the filament heater, C1-R1/R2-C2 should be in the PSU chassis.
Then, when you mount the filament regulator (near to the tubes), use a 1000uF 16V Panasonic FC or your favourite low impedance elko. Mount this on the regulator PCB, like George has done.
The same approach with the B+ PSU is recommended.
Keep the filament supply wiring away from the B+ wiring, when you connect the PSU chassis to the Signal Chassis.
Hi - vgeorge mentioned 5AR4 as a rectifier, and it may be interesting to compare notes about preferred rectifiers.
I've gone over to directly heated rectifiers - with DHTs I don't see the point of slow startup unless I'm missing something. Anyway, they sound better to my ears.
I'm having good sound with 5Y3 (80) or AZ1 mesh in my preamp. In my 300b SET amp I've been using 5U4G (5Z3) or recently a RCA 5T4 which surprised me since it's an ugly metal thing but actually has several strong points to the sound.
I've put all my Mullard GZ32,33,37 on ebay this week.
What are your experiences?
Andy
I've gone over to directly heated rectifiers - with DHTs I don't see the point of slow startup unless I'm missing something. Anyway, they sound better to my ears.
I'm having good sound with 5Y3 (80) or AZ1 mesh in my preamp. In my 300b SET amp I've been using 5U4G (5Z3) or recently a RCA 5T4 which surprised me since it's an ugly metal thing but actually has several strong points to the sound.
I've put all my Mullard GZ32,33,37 on ebay this week.
What are your experiences?
Andy
I'm planning to use a RCA #80 as rectifier, but iI would also like to try a Mullard GZ37 (I'm having a custom xfrm wound with 5 and 6.3 V sec).
Do you think it will be a waste of time as the #80 is clearly better?
Do you think it will be a waste of time as the #80 is clearly better?
The 80 and GZ37 are quite different - 80 is lower power direct heated, GZ37 is higher power indirect heated, more for larger amps like 300b SETs where it's popular.
If it's just for a preamp, the lower power rectifiers are nice like the AZ1 mesh and 80. If you're running the preamp and amp off the same supply, then try the 5U4 or 5T4 in octal. If you're using a 4 pin socket then you have the 5Z3 as a 4 pin alternative to 5U4G. I doubt if you'll miss the GZ37.
Andy
If it's just for a preamp, the lower power rectifiers are nice like the AZ1 mesh and 80. If you're running the preamp and amp off the same supply, then try the 5U4 or 5T4 in octal. If you're using a 4 pin socket then you have the 5Z3 as a 4 pin alternative to 5U4G. I doubt if you'll miss the GZ37.
Andy
Hi Theo,
Best regards
Thomas
That's how I would do it. In my case since I'm using LCL passive filtering for the filaments, I keep the last L of the filament supply and the last LC of the B+ supply in the preamp chassis. All the rest of the PSU goes to a separate chassis.
Best regards
Thomas