I just received my TSE-II board (thanks George) and was wondering if anyone has tried the JJ 2A3 in the board?
George: sent Paypal remittance for TWO each TSE-II boards
Oops, second Paypal for shipping, sorry...
Oops, second Paypal for shipping, sorry...
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"Saturation"
Almost certainly not.
SE OPTs (single ended output transformers) need to have properly "gapped" core laminations to insure against saturation of the core. I guarantee that this power transformer will work poorly as an SE OPT.
I have heard tell of using MASSIVE Push-Pull OPTs (say 60-80W rating) in lieu of an SE OPT, the idea being that the sheer mass of the core will limit saturation, but I haven't tried it myself, and I'm not sure what a viable PP/SE power ratio would be; 5:1? 10:1?
If you are looking for good, inexpensive SE OPTs, I STRONGLY suggest the Edcor XSE series. For the price, they are a screaming bargain.
EDCOR - XSE Series Output Transformers
Their only limitations are
(a) single output impedance (e.g. 8 ohms)
(b) limited bass reproduction (good bass requires a much heavier OPT)
However, they sound GREAT, especially (to my ears) relative to the larger Hammonds open-frame OPTs (which are also much more expensive.
Plus the Edcors come with an ultralinear tap, which I use a lot.
I think I've used about a dozen pairs of the Edcor XSE; never been disappointed.
I have always thought that a good inexpensive set-up would be a BI-AMP arrangement with a good Solid State amp for the bass, and a TubeLab SSE with the cheap Edcor OPTs above say 300-500Hz. Just a dream some of us had...
Almost certainly not.
SE OPTs (single ended output transformers) need to have properly "gapped" core laminations to insure against saturation of the core. I guarantee that this power transformer will work poorly as an SE OPT.
I have heard tell of using MASSIVE Push-Pull OPTs (say 60-80W rating) in lieu of an SE OPT, the idea being that the sheer mass of the core will limit saturation, but I haven't tried it myself, and I'm not sure what a viable PP/SE power ratio would be; 5:1? 10:1?
If you are looking for good, inexpensive SE OPTs, I STRONGLY suggest the Edcor XSE series. For the price, they are a screaming bargain.
EDCOR - XSE Series Output Transformers
Their only limitations are
(a) single output impedance (e.g. 8 ohms)
(b) limited bass reproduction (good bass requires a much heavier OPT)
However, they sound GREAT, especially (to my ears) relative to the larger Hammonds open-frame OPTs (which are also much more expensive.
Plus the Edcors come with an ultralinear tap, which I use a lot.
I think I've used about a dozen pairs of the Edcor XSE; never been disappointed.
I have always thought that a good inexpensive set-up would be a BI-AMP arrangement with a good Solid State amp for the bass, and a TubeLab SSE with the cheap Edcor OPTs above say 300-500Hz. Just a dream some of us had...
TSE has died
Hi, after years of happy listening I have screwed up my TSE (with 45s). One channel now has 140mA running through the 45 and the other has 0mA. I tried replacing a bunch of components (and added the TSE II mods at the same time), but nothing helps. Could someone look at these voltage readings (attached) and tell me if anything is way off? Both channels are within a couple of volts of each other. Thanks!!!
Hi, after years of happy listening I have screwed up my TSE (with 45s). One channel now has 140mA running through the 45 and the other has 0mA. I tried replacing a bunch of components (and added the TSE II mods at the same time), but nothing helps. Could someone look at these voltage readings (attached) and tell me if anything is way off? Both channels are within a couple of volts of each other. Thanks!!!
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I haven't used the JJ tubes specifically, but I'm currently using a pair of Chinese 2A3s in my TSE-II and have been very pleased with the results. They appear to be similar to the JJ tubes (300B structure with a 2.5V filament). I'd certainly give them a go.
Single Plate?
Does "300B structure" mean that these tubes are SINGLE PLATE?
On one hand, makes sense that they would use 300B internals, OTOH single plate 2A3s are historically as rare as hen's teeth (or cheap 300Bs). I did see some current production singel palates 2A3s years ago, but they were very high priced and rare...
I haven't kept-up with current 2A3 production, but I'd certainly be willing to try 2A3s again IF they were indeed single plates.
Does "300B structure" mean that these tubes are SINGLE PLATE?
On one hand, makes sense that they would use 300B internals, OTOH single plate 2A3s are historically as rare as hen's teeth (or cheap 300Bs). I did see some current production singel palates 2A3s years ago, but they were very high priced and rare...
I haven't kept-up with current 2A3 production, but I'd certainly be willing to try 2A3s again IF they were indeed single plates.
Thanks for responding. Looking at the plate structure, it pretty much looks just like their 300b, hilariously. OTOH, I ain’t buying NOS 2A3s....or even low testing ones. In any case, I think the JJ is a decent product that is supposed to sound very good.
I have other large envelope SET amps and I can get NOS for those much cheaper.
Cheers,
Greg
Thanks for responding. Looking at the plate structure, it pretty much looks just like their 300b, hilariously. OTOH, I ain’t buying NOS 2A3s....or even low testing ones. In any case, I think the JJ is a decent product that is supposed to sound very good.
I have other large envelope SET amps and I can get NOS for those much cheaper.
Cheers,
Greg
The new vendor's TSE-II boards arrived Monday (see UPDATE 3-18-21 in post #1). The new boards are a bit darker in color. That is the only visible difference.
Top board is old one, bottom is new, to right are old proto board stripped of most parts.
I have built one by stealing known good parts from two old prototype boards to save time. Testing will start soon.
Top board is old one, bottom is new, to right are old proto board stripped of most parts.
I have built one by stealing known good parts from two old prototype boards to save time. Testing will start soon.
Attachments
I'm having a weird problem with the TSE-II (300b). The left channel keeps drifting a fair bit. However I adjust the right channel, the left is always ahead.
The 5842s don't vary by more than 1v and the problem does not follow the tube, so its definitely not the 300b.
What should I be checking? Could it be a problem with R23 variable ?
The 5842s don't vary by more than 1v and the problem does not follow the tube, so its definitely not the 300b.
What should I be checking? Could it be a problem with R23 variable ?
George,
Very cool. Did you ever run the 46 in the TSE?
Obviously the B+ is much lower....
From memory, I ran them at the same B + of 275 ish, and about 23 - 25 mils.
Same for 47.
If I can find an entry in my notebook and it is different, I'll post a correction.
Same for 47.
If I can find an entry in my notebook and it is different, I'll post a correction.
46 in a Simple 45 amp
I have run them in UltraLinear (an off-label application, as UL wasn't around when they wrote the Cunningham data sheet) at about 34-35 mA in a Simple 45 point-to-point clone (powered by regulated P/S, with CCS on top of 5842 driver, but WITHOUT MOSFET).
Thread is here: "Simple 46" Amp, PLUS How About 46 Ultra-Linear?
No embarrassing redness, although I didn't run many hours, nor did I scope it.
At lower power, my 46s sounded thin and forward. Thickened-up nice with a little more current (sounds like a Cajun cookbook on making Roux), but mid 30s mAs might be pushing it...
I was using a variety of OPTs, but pretty sure most were 5K ohm.
I have run them in UltraLinear (an off-label application, as UL wasn't around when they wrote the Cunningham data sheet) at about 34-35 mA in a Simple 45 point-to-point clone (powered by regulated P/S, with CCS on top of 5842 driver, but WITHOUT MOSFET).
Thread is here: "Simple 46" Amp, PLUS How About 46 Ultra-Linear?
No embarrassing redness, although I didn't run many hours, nor did I scope it.
At lower power, my 46s sounded thin and forward. Thickened-up nice with a little more current (sounds like a Cajun cookbook on making Roux), but mid 30s mAs might be pushing it...
I was using a variety of OPTs, but pretty sure most were 5K ohm.
The 47 looks like a good option as well.....
I like B+ builds in this range because I like using the 80 rectifier, as I have lots of them (globes)!
Cheers,
Greg
Harry,
I’m surprised they sounded thin at 5k primaries (as opposed to 7k). I certainly know what you are saying about lower bias yielding a thin and forward presentation. I of course don’t know if you measured distortion, but I would guess that the distortion profile changed from dominant 3rd, to dominant 2nd as you went up in bias (at a given load).
Cheers,
Greg
I did NOT do any measurements, but your guess about 2nd-order distortion sounds about right.
The whole 46 project got sidetracked when I tried a EH 300B in the Simple 45 Clone, but thru the BIG Edcor SE OPT (25W CXSE)
I usually don't spend like that ($100 tube +$100 OPT per channel, not to mention the 5842), but I accidentally had everything in stock for some reason or another.
BAM! as Emeril would say, everything just came together. Deep bass, smooth as silk, and (most important) 'UGE headroom compared to every dinky DHT I've tried over the years/decades; 71A,45,46,2A3
Probably not as detailed or "precious" as the 45/46 family, but (if properly driven) the 300B fills the house. I mean FILLS THE HOUSE.
THEN, I added a MOSFET clone board so it's now a +/- credible TSE-I clone. Not a gigantic difference, but noticeably better.
In my mind, the most important things about George's evolved TSE circuit are:
(1) an adequate (single stage) driver for the 300B (ie 417A/5842) although the current prices are killin' me..
(2) 10M45 plate load; works great where ever I try it (including on top of 6SL7 for a 6AV5 SE amp), and of course simply MAKES the SSE what it is
(3) Regulated DC filament supply. This has been a revelation after spending YEARS chasing HUM with a balance pot..
(4) MOSFET coupling; I'm not convinced that this rises to the level of the other improvements, but it's not expensive and does seem to give some headroom UMPH. Probably wasted on me with my old-man musical tastes...
See the photo. Note:
(a) Pete Millett Fils P/S, analogous to George's on-board filament P/S
(b) big&crude MOSFET "coupling" board (ie between driver an 300B), and
(c) tiny CCS (10M45) at the wrong end of the chassis, don't know why
(d) deck pot for bias adjustment
Based on this implementation, I ordered a couple of TSE-II boards (which I'm using for Mono Blocks, and will order a couple more once George gives the thumbs-up on the Chinese sourced ones.
The whole 46 project got sidetracked when I tried a EH 300B in the Simple 45 Clone, but thru the BIG Edcor SE OPT (25W CXSE)
I usually don't spend like that ($100 tube +$100 OPT per channel, not to mention the 5842), but I accidentally had everything in stock for some reason or another.
BAM! as Emeril would say, everything just came together. Deep bass, smooth as silk, and (most important) 'UGE headroom compared to every dinky DHT I've tried over the years/decades; 71A,45,46,2A3
Probably not as detailed or "precious" as the 45/46 family, but (if properly driven) the 300B fills the house. I mean FILLS THE HOUSE.
THEN, I added a MOSFET clone board so it's now a +/- credible TSE-I clone. Not a gigantic difference, but noticeably better.
In my mind, the most important things about George's evolved TSE circuit are:
(1) an adequate (single stage) driver for the 300B (ie 417A/5842) although the current prices are killin' me..
(2) 10M45 plate load; works great where ever I try it (including on top of 6SL7 for a 6AV5 SE amp), and of course simply MAKES the SSE what it is
(3) Regulated DC filament supply. This has been a revelation after spending YEARS chasing HUM with a balance pot..
(4) MOSFET coupling; I'm not convinced that this rises to the level of the other improvements, but it's not expensive and does seem to give some headroom UMPH. Probably wasted on me with my old-man musical tastes...
See the photo. Note:
(a) Pete Millett Fils P/S, analogous to George's on-board filament P/S
(b) big&crude MOSFET "coupling" board (ie between driver an 300B), and
(c) tiny CCS (10M45) at the wrong end of the chassis, don't know why
(d) deck pot for bias adjustment
Based on this implementation, I ordered a couple of TSE-II boards (which I'm using for Mono Blocks, and will order a couple more once George gives the thumbs-up on the Chinese sourced ones.
