Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: rrputnam1 on February 04, 2026, 02:13:43 pm
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I am embarking on a project to build Sluckey's Dual Lite British amp. I purchased a Hoffman Stout Chassis v2 for the purpose. I'm wondering if anyone has any recommendations for transformers. I would like to use an 8 OHM output transformer if possible. I'd also appreciate any other advice. I will post images as the project advances. Thank you.
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Mojotone - Marshall style 18 watt transformers fit in this chassis.
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Sluckey's designuses a Hammond AO-23279-1 power transformer which has 315 VAC, 5 VAC, and 6.3VAC for filaments. The Mojotone has 290 VAC, 5/6 VAC, and 6.3. Will the difference between 290 and 315 pose any problems?
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Sluckey's designuses a Hammond AO-23279-1 power transformer which has 315 VAC, 5 VAC, and 6.3VAC for filaments. The Mojotone has 290 VAC, 5/6 VAC, and 6.3. Will the difference between 290 and 315 pose any problems?
no
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I made one of these using both transformers out of a Vox Night train clone, no idea of the specs as they were in Chinese, iIrc the pt gave out about 320v so mine's a little hotter as I used ss rectification.
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Whereabouts are you?
If you're in the UK, this fella was one of the first folk to reproduce 18 watt transormers. He will add you to a production run. His email style is a little terse btw .
https://www.ebay.co.uk/sch/i.html?item=267555083650&rt=nc&_trksid=p4429486.m3561.l170197&_ssn=steves025uk
He has very good prices and lots of folks have used his stuff.
If you're in the US, mojotone, Heyboer and the usual suspects, I guess:
https://mojotone.com/products/british-style-18w-output-transformer-direct-replacement-for-the-marshall-r-18w?variant=41689653248096
I did a fair bit of PM-ing back and forth with Sluckey, in the end I went for a 275V transformer, not the normal 300, as the latter generally gives too high B+ with current voltages.
Do keep updating your thread - I have a lot of bookmarks for the Dual Lite, there are suggested modifications. It was stated on this site that you can get noise from the unused channel so worth thinking about modding. I THINK the suggestion is here, from CrocMule. Would love to see other's feedback (My Dual Lite build is extremely delayed as I seem to be building a modular synth).
https://el34world.com/Forum/index.php?topic=32297.0
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If you're in the UK, this fella was one of the first folk to reproduce 18 watt transormers. He will add you to a production run. His email style is a little terse btw .
https://www.ebay.co.uk/sch/i.html?item=267555083650&rt=nc&_trksid=p4429486.m3561.l170197&_ssn=steves025uk
He has very good prices and lots of folks have used his stuff.
I agree, my friend has this output transformer in an 18watt and they are nice, steves025uk also makes the Valvepower 18w guitar amp and the Leak 20 rebuilds too
https://valvepower.co.uk/index.html (https://valvepower.co.uk/index.html)
https://valvepower.uk/index.html (https://valvepower.uk/index.html)
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I can vouch for Primary Windings and Modulus...both good to deal with and quality items that I've used a lot. Also I use transformer equipment when I need something built specifically. I believe Modulus will also do that.
https://primarywindings.com/product-category/outputtransformers/ (https://primarywindings.com/product-category/outputtransformers/)
Amp Maker PWAM01 275V-190V@ 160mA 6.3V@3A - Primary Windings (https://primarywindings.com/product/amp-maker-pwam01-275v-190v-160ma-6-3v3a/)
https://modulusamplification.com/18-watt-output-transformer-4---8---16-ohm-secondary-3101-p.asp (https://modulusamplification.com/18-watt-output-transformer-4---8---16-ohm-secondary-3101-p.asp)
https://modulusamplification.com/18-watt-power-transformer---select-mounting-3100-p.asp