1484 silvertone speaker 8ohm???

[VintageSeb]

Hi, I'm new to the forum. I recently bought a 1484 silvertone head amp it has 35-40 watt, and now I need a speaker cabinet, but I'm confused about how many ohms I can run this amp on. The amp is rated at 4 ohms , but the guy I bought it from said I can easily run this half or twice the rated independence. So can i run this through a 8 ohm speaker cabinet???

[Bruce / Mission Amps]

Hi, I'm new to the forum. I recently bought a 1484 silvertone head amp it has 35-40 watt, and now I need a speaker cabinet, but I'm confused about how many ohms I can run this amp on. The amp is rated at 4 ohms , but the guy I bought it from said I can easily run this half or twice the rated independence. So can i run this through a 8 ohm speaker cabinet???

Well, two things, I don't think a 1484 can really make 40 watts and the 8 ohm speaker will actually double the impedance not halve it so keep that in mind.
But the OT is small in these amps and you'll have to be careful if you decide to run the 8 ohm speaker load.
I think if the OTs were bigger in those amps I'd say it will be OK but I've replaced a few of those OTs with reissue Pro reverb OTs for a reason!
Here is the one I'd use:
http://allenamps.com/images/ot381.jpg
Allen Amps TO35MT $59.00
A high quality replacement output transformer for Vibrolux™, Pro™, Bandmaster™, Vibroverb™ and Tremolux™ amps and "vibroclone style" projects. Custom wound in the USA by Heyboer on a paper tube with paper layered and specially interleaved windings with a 4K ohm primary and both 4 and 8 ohm secondary taps for one or two speaker set ups. As used in the Accomplice, Brown Sugar and Encore amplifiers. Special low insertion loss lamination steel for increased output. Black oxide finish with 12" Unistrand pretinned leads for fast installation. 3-9/16" mounting centers. 2.4 lbs. A very sweet sounding transformer for 2x6L6 amps. Stainless-steel mounting hardware included!

[tboy]

Every 1484 I've seen has an extra tap on the output side of the OT that isn't used. Anyone know what impedance it is?

[VintageSeb]

Well, two things, I don't think a 1484 can really make 40 watts and the 8 ohm speaker will actually double the impedance not halve it so keep that in mind.
But the OT is small in these amps and you'll have to be careful if you decide to run the 8 ohm speaker load.
I think if the OTs were bigger in those amps I'd say it will be OK but I've replaced a few of those OTs with reissue Pro reverb OTs for a reason!
Here is the one I'd use:
http://allenamps.com/images/ot381.jpg
Allen Amps TO35MT $59.00
A high quality replacement output transformer for Vibrolux™, Pro™, Bandmaster™, Vibroverb™ and Tremolux™ amps and "vibroclone style" projects. Custom wound in the USA by Heyboer on a paper tube with paper layered and specially interleaved windings with a 4K ohm primary and both 4 and 8 ohm secondary taps for one or two speaker set ups. As used in the Accomplice, Brown Sugar and Encore amplifiers. Special low insertion loss lamination steel for increased output. Black oxide finish with 12" Unistrand pretinned leads for fast installation. 3-9/16" mounting centers. 2.4 lbs. A very sweet sounding transformer for 2x6L6 amps. Stainless-steel mounting hardware included!

Thanks for the info, but do you think replacing the OT will affect the sound much, because I still want it to that classic dirty blues sound?

[soundmasterg]

The stock 1484 output transformer has a 4 ohm tap, and an unused 2.6 ohm tap. The same output transformer (two of them) is used in the 1485, which uses the 2.6 ohm tap (two of them), and not the 4 ohm tap. In both applications, this output transformer is greatly undersized, and as a result often blows in the stock circuit. The stock 1484 puts out about 25 watts RMS and thats it. I modded the piss out of my brother's and one of the things I did was to increase the voltage feed to the power tube screens. as a result, his puts out 30 watts RMS, but there is no way with that stock output transformer that it puts out more than that. We used to run his into an 8 ohm cabinet for years. It is easier on the tube in some ways to do this, and sounds great for leads as the tone gets all compressed and dirty, and it narrows the frequency response somewhat. That said, it sounds MUCH better through a 4 ohm speaker cabinet into the 4 ohm tap on the amp, and it puts out more volume this way too. We've been waiting for his stock output transformer to blow ever since I modded it and it works just fine with no complaints, so maybe he got a good one.

Greg

[Gollum]

I've run my 1484 into a lot of 8 ohm cabinets without much issue. My amp is 100% unmodified currently.

I also don't run the thing wide open very often, and when I do it's normally on my 4x12 set to 4 ohms.

I personally like the "mild" nature of this amp's output levels. Makes it fairly usable.