No worries. I was looking for around £200 the pair inc shipping and insurance.Oh, sorry, I got over excited, and misread 1640 as 1628, so not quite what I'm after. Thanks anyway.
Thanks. That curve is very different from the Hammond 1628SEA, which rolls off smoothly at the top. Tubelab says the SEA is curtailed at the top compared to the Edcor and that the size of its core means a magnetic inertia that can destroy low level information......
Most of the comments and measurements that these comments are based on were made over 15 years ago. I have learned a lot more about tube amps and OPT's in those years. Two pieces of information from the 2006-2007 experiences remain true however.My misgivings about the SEA have been sown by Tubelab. Unfortunately the Edcor has only one output tap and would cost me over £100 more than the Hammond.
5K ohms is a middle of the road load for an EL84. You could get a bit more power with the textbook 3500 ohms in triode mode, but some pentode applications prefer as much as 7 to 8K ohms. 3K ohms is the accepted "audiophile" load for a 6550A or KT88 wired as a triode.However they list the 5k primary model for EL84s and the 3K version for KT88s which is curious. Which model did you buy?
No problem, the old data is still valid, but I have found ways to squeeze more performance from a given OPT in the past 15 years. This just happens to work wonders on Hammond OPT's.George
I did not see your post before I posted the links to your website.
Years a go builder Decware used Hammond OPTs, afew years later/now they are using Edcor apparently, certainly there was a SQ reason imo.Useful info FullRangeMan. Thanks. Hammond seem to have addressed the top end nasty issue in the SEA. They have also reduced the copper losses from 439R t0 171R. The leakage inductances look a bit high though.
My misgivings about the SEA have been sown by Tubelab. Unfortunately the Edcor has only one output tap and would cost me over £100 more than the Hammond.
I want to build a single ended KT88 amp and/or an 807. In the UK I can source the Hammond 1628SEA and the Edcore CXSE25-8-5K. I've seen some discussion of these two. There have been some disparaging remarks about the Hammond's top end. If anyone has experience of these I'd appreciate hearing about it. I would have liked to chose the Hammond as they have several output windings/taps, that give matching flexibility and are considerably cheaper than the Edcors. However I don't want to sacrifice sound quality if there is a big difference. Cheers. Matt
Years ago SAC-Thailand tested various OPTs,
The Hammond 1628SE was not good:
personally I am looking to find a right trafo for my purpose; so the right tests can help me to understand.
And can't be only a frequency answer at low level that can tell me the information.
Of course everyone has a personal point of view.