Angela Instruments

Open style with minimum 5" long primary leads, secondary solder lugs for convenient secondary connections. Tables provided with each transformer listing 90 precalculated impedance ratios. Primary impedances from 1,200 to 25,000 ohms, so you can use virtually any output tube, single-ended or push-pull. The three primary wires obey the standard color code for push-pull output tranformers; the blue and brown wires are plate leads, the red wire is the center tap. For SINGLE-ENDED use of the output transformers in the 125 Series, simply use the two blue and brown plate lead wires; just tape off the red center tap wire. We have recently confirmed this hookup information with the technical staff at Hammond. Secondary impedances from 1.5 to 15 ohms. See this page for 125 Series Impedance Table. For more information on using this table check out the commentary on the Simple 6V6 Guitar Amp Project under the How To Section of this website.

HAMMOND UNIVERSAL OUTPUT TRANSFORMER IMPEDANCE TABLE
For 125 Series

The following is some commentary taken from our How To Section 6V6 Guitar Amp Project on how to read this chart:

If you're using the popular Hammond 125E you'll have to choose which primary impedance you'd like to try; since many are available (between 1.2K and 25K) offering different tonal choices. The 'textbook' primary impedance choice for a single-ended 6V6 is around 5K, athough you might want to try anything between 3K and 8K. Lower primary impedances will give you slightly more power output and more distortion, the classic design 'trade-off'. For hi-fi, a higher than textbook primary impedance is currently fashionable in hobbyist circles, since it offers a more linear sound with less distortion at only slightly less power. For guitar amps, anything goes. The impedance YOU dig is the 'good one', and this is pretty easy to mess around with if you choose the 125E. Even a monkey with a soldering iron might hit the right two solder lugs (there's only six lugs....all found on the secondary side of the coil). Some classic vintage guitar amps apparently used lower than textbook primary impedance output iron by design. Keep in mind that such a choice was usually a few pennies cheaper in the '50s, so maybe that had something to do with it. Look at the top column of Hammond's hookup diagram (found on the packing box of the transformer) and find your speaker impedance (e.g. 8 ohms), then scan down to the closest primary impedance for a single 6V6 (for starters, try "5600" ohms...), then scan over to the left hand column and it'll tell you exactly which two of the available six lugs to hook your dang speaker to, right? For example, if you have an 8 ohm speaker and want to select a primary impedance of "5600" ohms, hook the two speaker terminals to lugs 1 & 5. Isn't D.I.Y. guitar amp building easy? You know it! By the way, the 125E was designed as a 'Swiss Army Knife" push-pull OR single-ended transformer: for single-ended use in this project, use the BLUE and BROWN wires only, hook 'em up to the same circuit points as you would the Fender 10W output iron described above. The BROWN wire of the 125E goes to lug #3 (the plate) of the 6V6GT, the BLUE wire goes to lug #4 (the screen grid) of the 6V6GT. Just 'cap off' the additional RED wire (the center tap...) with a wire nut. Choose the appropriate two lugs on the secondary side of the 125E according to the impedance ratio table included with that transformer. By the way, it doesn't matter which of the two output lugs you designate as positive (+) or negative (-), just hook the two wires to your speaker and it'll work fine.

Voice Coil Impedance Connect To:	1.5 ohm	2 ohm	3.2 ohm	4 ohm	6 ohm	8 ohm	12 ohm	15 ohm
1 - 2	27000
2 - 3	18000	24000
3 - 4	16500	22000
4 - 5	10000	13500	21600	27000
5 - 6	8500	11000	18000	22000
1 - 3	5400	7200	11500	15000	21600
2 - 4	4200	5600	9000	11200	16800	22500
3 - 5	3300	4400	7000	8800	13200	17600	26400
4 - 6	2400	3200	5100	6400	9600	12800	19200	24000
1 - 4	2150	2900	4600	5800	8700	11600	17400	21500
2 - 5	1550	2050	3300	4100	6150	8200	12300	15500
3 - 6	1300	1700	2700	3400	5100	6800	10200	12800
1 - 5		1400	2200	2800	4200	5600	8400	10200
2 - 6			1700	2100	3150	4200	6300	8000
1 - 6			1200	1500	2300	3000	4500	5600

Due to the large number of Hammond model numbers it is not possible to keep all items in stock.
We have some Hammonds on the shelf but otherwise we order them as we get orders.
Out of stock items will be shipped approximately one week after you place your order. We can special order any Hammond product for you. Let us know the Hammond model number and we will quote you a price.

Hammond Universal Single Ended or Push-Pull Output Transformers

Hammond Output Transformer 125A

Hammond Output Transformer 125B

Hammond Output Transformer 125C

Hammond Output Transformer 125D

Hammond Output Transformer 125E

Hammond Output Transformer 125H