[docali]

Hi,

last weekend we compared my DIY SB TX-103 step-up transformer against the Audio Note AN-S2 and the Shelter transformer. Equipment was a Garrard 401 from Loricraft with Origin Live Silver tonearm and Shelter 301 cartridge, Adio Note Meishu amplifier and Audio Note speakers.

The TX-103 was wired in 1:10. During the comparison it came out that the the TX-103 lost in every aspect against the AN-S2 and the Shelter which had much more transpareny, more room and a wider bandwidth. The TX-103 sounded compressed against the others. Using another cartridge (Shelter 90X) the result was the same.

Did I something wrong??? Can the TX-103 be normally seen in the range of Audio Note or Shelter transfomrers?

Regards,
Bernd

[John Chapman]

Hello!

Sorry it did not work so well - at least on the testing recently. The tx103 has usually fared rather well in comparisons but I am not about to use that as an excuse for the performance you had! Just so I can get my bearings can you let me know:

1- Is it a raw tx103 (vintage and from where) or an assembled MU setup. This will maybe rule out some defect - since MU setups are all fully tested (sonically and via the AP system 2) here prior to shipping. Still not very likely since tx103 defects would be rare and also would most likely only affect one channel.

2- What is the ratio of the other 2 units - this will change the effective loading the cart will see - making quite a difference possible sonically due to that load change - if there is one.

3- What load is after the step-ups and was it changed for each step-up tested?


These things will help see what might be up.

Thansk!

John

[docali]

Hi John,

I got my pair of TX-103 transformers directly from Stevens and Billington.
With the information given from their Website on your valueable information about the MU-stepup I wired it to 1:10 because the Shelters have 0.5mV output and this gives me 5mV for the RIAA stage. Additionally my stepup has a switch at the output for shunting with a 12k resistance. But in all tests we found that is was better without the resistor resulting in a load of 470 Ohm for the cartridge.

The stepup ratio for the Audio Note transformer is about 26dB and the Shelter even more (i think 33dB). Shelter and AN-S2 were nearly at the same level but we prefered the Shelter for its natural and more open sound. The AN-S2 had a better low frequency resolution.

I even burned the TX-103 in for a week using a tuner at the input side as described in the Web. But now I am a little disappointed because the TX-103 was highly praised by several people.

Best regards,
Bernd

[John Chapman]

Hello!


Sorry for the delay replying. I wanted to speak with S&B to get any info he might have. Just talked to him this morning. Here is the best plan I can come up with:

1- Since both the other units you are testing with are at a higher ratio go ahead and re-wire for 26db gain. Just let me know if the wiring is not clear on the drawings and I'll post a full description of what to change.  At least it then 'should' be a closer comparison gain wise. As a side question - how was the gain level of the tx103 at 1:10 compared to the others. It should have been marginally lower than the AN but not an extreme difference.

2- If comparing at 1:20 does not yeild any better results then we should confirm operation is correct. Some restistance readings on your end will start that process.

3- If you are close to me here I'd be happy to bench test and sonically test them here to see if the match what I'd expect. If you are closer to Jonathan at s&b then he'd do the same at his shop.

4- Please e-mail or call Jonathan at S&B. He was dissapointed to hear of someone having iffy results and would like to make contact directly with you.

I am sorry again that they did not perform better out of the shoot. The tx103 has just super technical performance - dead flat from about 5hz to well over 100khz and then very well behaved above that. Several folks have compared to lots of other step-ups (including some legendary units) and although system differences come into play the tx103 should fare really quite well in any case. That fact it was so bad in your comparison leaves hope that there may be something up that we can fix!

Thanks!

John

[docali]

Hi John,

thank you very much so far for your effort!

I will rewire my DIY stepup to 1:20 but have to ask my local audio dealer to redo the tests because it was his equipment. Documentation is very good so it's an easy job

Because I live in germany it should be more convenient to contact Jonathan at S&B. Would you please provide me with his personal contact information via the pm function of this forum? I will keep you informed!

Beside this, to confirm your question. Yes, the AN was slightly louder than TX-103 (1:10). The Shelter TX had even more output level.

What do you mean with resistance reading? Should I check primary or secondary dc resistnace of TX-103?

Best regards,
Bernd

[John Chapman]

Hello!

Thanks for your efforts to continue testing.  Jonathan can be reached at:

audiotransformer@beeb.net

OR by phone:

+44 (0)1825 890111

It could be that the system in question (at the local dealers shop?) is much happier with a higher input level to the phono stage.  Since the relative performace in the test was 20db to 26db to 33 db would indicate it may be a factor.  If you have it installed at home as well please let us know what carts,loads, stages, etc it is wired to and what you have found. Since sometimes these things come down to system optimization (loading, gain, table vta, etc)  it is likely most important to get it working best for you and not for your local dealer!

To check resistance of the wired tx103:

The primary hot to ground should read about 3.5 ohms at 1:10 or 1.2 ohms at 1:20

The secondary hot to ground should read about 140 ohms

These reading will vary depending on your meter and some meters do not like to read the high inductance of the transformer. My cheap meter reads them fine but my 'good' bench meter does not.....

Please let us know how you make out and we'll do our best to sort it all out.

Thanks!

John

[docali]

Hi John,

first I will describe my equipment at but it is quite similar to that of my local dealer:
Source: Wilson Bennesch turntable and Circle, ACTII tonearm, Shelter 901
Pre-Aplifier: Audio Note M2 Special or an DIY Anzai SRPP
Amplifier: Audio Note P2SE
Speakers: Audio Note AN-J Spe

Yesterday I wired the TX-103 to 1:20, sound seemed to be a little more dynamic. I think it will take a little time to redo the comparison with the other two transformers. For me it sounds better to have no shunting resistor at the output (at the moment my TX-103 has a switch to shunt the output with a 12k resistor -> 47k||12k).

DC resistance is in the range you described: 1,4 Ohm for primary and about 134 Ohm for secondary. Looks ok?

Meanwhile I will contact Jonathan...

Best regards,
Bernd