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Output Transformer options for SSE

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Hi, total noob to diy tubes but I'm trying to learn a bit more about the tubelab SSE. My speakers are Klipsch Forte 1's, so fairly sensitive.

For output transformers, the tubelab site gives several options and pros/cons. I'm in Canada, so my choices are somewhat limited without paying an arm and leg on conversion and shipping. Hammond transformers seem to be readily available here. Other brands not so much.

The 125 series seems to be cheap but has limited frequency response. Even the largest 6lb 125GSE one, and I haven't seen any SSE builds using this version (would love to hear if anyone has).

So, it looks like the better (but pricier) option would be the big 1628SEA. But the tubelab site says that it is NOT very good with high efficiency speakers.

So I'm left scratching my head a bit on what the best route would be?
 
I am a tube bush leaguer as well, I have not heard a large OPT can be an issue for sensitive speakers before I read the SSE manual. I would like to understand this better, many quality tube amps from the 50s and 60s used large OPTs to drive very sensitive speakers successfully.

I have an el84pp amp which has good high/low response with smallish (4-5lb) OPTs. I would like to find similar price/performance/cost for the SSE.

So that leads to a question about the big OPTs, should I go with the 9lb edcors, give up some bass and make up for it by running KT88s? Is there a middle weight contender available new (not on eBay) at a reasonable price?

Maybe we can get some SSE builders to chime in? What OPTs did you use? Are you happy with them? What’s the response like?
 
Antique electronics sells the one electron UBT series. I’m using the UBT-2 in a KT-88 build and they are quite satisfactory. I’ve also used the small Edcore and they are surprisingly good, especially for the money. These are low powered amps. A big transformer is not needed.
 
Antique electronics sells the one electron UBT series. I’m using the UBT-2 in a KT-88 build and they are quite satisfactory. I’ve also used the small Edcore and they are surprisingly good, especially for the money. These are low powered amps. A big transformer is not needed.

Both are options that I looked at but with exchange rate and shipping, they become VERY expensive for us Canucks ;)
 
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Both are options that I looked at but with exchange rate and shipping, they become VERY expensive for us Canucks ;)

I found the same thing. Here's a good summary I wrote a while back on this topic (specifically for Canucks): SE Output xfmrs....who are the current suppliers for not many $$$

That whole thread is probably worth a read if you like to over-analyze things like most of us around here. :)

By the way, from that list I chose:

Transcendar TT-338-OT - "10w"/4lbs. - $95 USD x 2 + $49.60 shipping (flat rate) = $239.60 USD = $319.35 CAD (I was charged $24 in border fees / taxes on top of this)

and (for schlitz n' giggles)

Laidy's (Chinese Cheapies) - "8-10w"/2.2lbs - $80 CAD per pair, shipped to your door (no border hit).

I have not completed my amp so I have not tried either of these, but in my mind the Transcendars are a better choice than the big Hammonds because they work out cheaper (after all is said and done) and they have a better reputation for sweet sound. The big Hammonds are virtually unbeatable for bass, but there are claims (and measurements) of not-so-great top end performance and lack of efficiency. They seem like overkill for a 6-10 watt amp, but maybe that's just me.

Note: I finally have all the parts to finish my SSE amp build. If you aren't in a rush, I'll be reporting my experiences with both the Transcendars and the Chinese Cheapies in the coming weeks.
 
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I've used Transcendar, Merit, Edcor, Hammond ( 125ESE ), and cheapie chicom on SSE builds.

Several people, including myself, have measured frequency response and distortion with the 125ESE Hammond's, and a search here should find the posts. I'm not going to advocate for or against them, but their performance is not as dire as some make it out to be.

That said, although there are some good values to be had in inexpensive transformers, I think OPT's are pretty much you get what you pay for.
 
That said, although there are some good values to be had in inexpensive transformers, I think OPT's are pretty much you get what you pay for.

I don't mind paying a bit more for the bigger hammonds, it was the comment on the build site that said they are not good for efficient speakers that had me worried. I'd be curious to see if this has been observed by others.
 
There are about as many opinions on OPT's out there, as there is on which car to drive. As with a car, the first question is what are you going to use it for.

Do your speakers have significant response below 70 Hz. Do you listen to bass heavy music at high volume levels? Do you have a subwoofer, and if so, how is it connected? How efficient are your speakers? What output tubes do you plan on using? How big is your listening area......

Will you even build / buy different speakers that change the answers to these questions?


bigger hammonds, it was the comment on the build site that said they are not good for efficient speakers that had me worried.

If the OPT's are large, they contain more iron and copper than small ones. The resistive losses will be higher. The larger iron core requires more energy to change it's magnetic domains, because there are more of them. If your amp idles along at 100 milliwatts in normal use because you have 105+ dB speakers, you would be better off spending the OPT money on better quality small OPT's. The big Hammonds do absorb quite a bit more energy than others I have tried, and some detail is lost when operated at low levels.

When I had the FH3 speakers set up in my 10 X 10 foot room in a near field situation I preferred the sound of the small Edcors or the Hammond 125CSE over the sound of the big 1628SEA. Now that I'm in a 2000 sq foot basement, the FH3's don't put out enough sound for small OPT's.

If you have big speakers with good low frequency response, the bigger OPT's may be advantageous.

Most smaller speakers have a peak in their impedance in the under 100 Hz range. My "8 ohm" Yamaha's are about 25 ohms at 70 Hz. If you have a subwoofer that is connected across the speaker outputs of the SSE, the impedance peak in your main speakers will cause the frequency response of your subwoofer to have peaks, possibly leading to booming bass. Sometimes a bit of knob twiddling on the sub can iron it out, but sometimes you can't fix it. If your sub is fed from a line level signal from before the SSE, then this is not the case.

For most people a good quality OPT in the 3 to 5 pound range is the best overall compromise. I bought a bunch of Transcendars for a good price about 15 years ago when Gerry "retired" the first time. They are very good OPT's, but I have no experience with his current stuff. The overall response from current users if quite good. Same thing with Electra Print, I have no recent experience.

I have not tried any of the 125 series Hammonds other than the 125CSE, and it is 15 years old. they did measure far better than their published specs and currently live in a 6V6GT based SSE that makes a nice 2 WPC. They did not cut it when trying to slam some 96dB 15 inch speakers around with KT88's in an SSE, but the Transcendars did work fine in that situation and are still in the amp.
 
There are about as many opinions on OPT's out there, as there is on which car to drive. As with a car, the first question is what are you going to use it for.

Do your speakers have significant response below 70 Hz. Do you listen to bass heavy music at high volume levels? Do you have a subwoofer, and if so, how is it connected? How efficient are your speakers? What output tubes do you plan on using? How big is your listening area......

Will you even build / buy different speakers that change the answers to these questions?

Sure, should have stated this up front. This would be driving a pair of Klipsch Forte 1's (specs here: https://f072605def1c9a5ef179-a0bc3f...cdn.com/product-specsheets/forte-brochure.pdf)

I basically only listen to vinyl via 2-channel in fairly large room (approx 15x25 that opens up to another area). Mostly classic rock but enjoy acoustic stuff and 90s grunge as well. Usually listen at reasonable levels but do like to crank it from time to time when the family is not home ;) I intend on keeping the Forte's for the near future as I have already invested in Crite's upgrades.

So given your comments above, I'm guessing the bigger hammonds would be the way to go, even with these high efficiency speakers?
 
I found the same thing. Here's a good summary I wrote a while back on this topic (specifically for Canucks): SE Output xfmrs....who are the current suppliers for not many $$$

That whole thread is probably worth a read if you like to over-analyze things like most of us around here. :)

Cogitech, that is a terrific summary! Exactly what I was looking for in terms of available options. Out of curiosity, what was your total cost of parts for your SSE build?
 
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Cogitech, that is a terrific summary! Exactly what I was looking for in terms of available options. Out of curiosity, what was your total cost of parts for your SSE build?

Total parts cost for my build is a bit over $800 CAD (tax in). This includes the optional choke and a big motor run cap. It does not include power tubes, driver tubes and the extra Chinese OPTs. I had budgeted $700, but then I decided to add some extras like voltmeters, ammeters, VU meters, extra tubes...

It is a lot of money, but I decided that life is too short and I really enjoy this hobby and listening to music through the components that I build. I've cut down on the single malt scotches for a while - a small price to pay, IMHO.
 
Total parts cost for my build is a bit over $800 CAD (tax in). This includes the optional choke and a big motor run cap. It does not include power tubes, driver tubes and the extra Chinese OPTs. I had budgeted $700, but then I decided to add some extras like voltmeters, ammeters, VU meters, extra tubes...

It is a lot of money, but I decided that life is too short and I really enjoy this hobby and listening to music through the components that I build. I've cut down on the single malt scotches for a while - a small price to pay, IMHO.

NOT THE SINGLE MALT!!!:drunk::boggled:

I kinda figured it would be around that much. I'm still trying to land on whether to do the hammonds or the transcendars like you did. I'm going to source out my parts list and see what I'm looking at. We may be hunkered down for a while so may be a good time for a project.

PS. Bushmills "Black Bush" is an excellent irish whiskey that is great bang for the buck. No single malt but very drinkable!
 
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I certainly don't want to push you one way or the other on the OPT selection because it is a very personal choice, but I just have to remind you that your speakers are 98dB efficient (!!!). Even when the family isn't around, I really doubt you are ever doing to use more than 10 watts, which will result in over 100dB SPL. That's *******' loud, man!

I like to use this page to get a sense of what power I need - AllegroSound * AllegroKnowledgeBase * Amplifier Power Calculator * (calculator is down the page a bit).

I'll check out that whiskey!

P.S. I have an SPL meter and when I turn things up to what I consider "loud" (loud enough that conversations become difficult) I very rarely see 92-93dB peaks, almost always in the mid to high 80s. At "normal" levels I am generally in the high 70s and low 80s.
 
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Hey Carbon13, I got my amp up and running with the Transcendars. I am very pleased with the sound, however I have not tried the cheap Chinese ones yet so I cannot provide any opinion/comparison. It will probably be a few weeks before I do that (ran out of solder and had to order online). Going to pick up a bottle of the Black Bush today!
 
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Hey Cogitech, Congratulations!!

I was actually following along and was super excited for you! Wish you were closer so I could come hear it in person (post social distancing of course ;)

I've been thinking a lot about the SSE project and it is something that I want to do but I have a lot of $$ invested in my Fisher 500c so I figured I should probably try to get the most enjoyment out of it before I do anything else.

So my current projects are 1) rebuild my Klipsch Fortes with recapped crossovers and new titanium tweeter and 2) try some tube rolling with the Fisher. I figure that should keep me busy for a while and then I can decide whether or not to go down this rabbit hole! I suspect that I'll eventually decide to build an SSE but I am still a bit nervous about it.

Enjoy the black bush!!
 
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Thanks, man!

It took me a long time to take the plunge and order the SSE board from George, but in hindsight I don't know why I waited so long. On the other hand, it sounds like you have plenty of stuff to tinker with and that's a big part of the pleasure of this hobby. I tinkered and heavily modded an EL34 push-pull amp and enjoyed listening to it for several years. Great fun, but I have to say it is much more satisfying to build an entire amp.

A little over a week ago I turned 50 and received a bottle of 15 year MacAllan triple cask from my wife. I need to get something else in the house to drink because the temptation to drink the MacAllan is overwhelming. I am actually really excited to try the Black Bush. The description I read sounds delicious.
 
Well, it's no 15yr MacAllan single malt but it's a great everyday Irish whiskey that I enjoy. I think it's great bang for the buck as whiskeys go.

Yep, I love the idea of the SSE project and can just imagine how rewarding it was to fire it up for the first time and hear something that you built. Must have been a great feeling indeed! Deserving of a celebratory whiskey!
 
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