If your output transformers are set up with a 4 ohm output tap only, then you will get a little more power if you replace them with transformers with an output winding impedance that matches your speakers. But, the difference won't be all that much. What you will notice is that the overall frequency response should improve. Now, if you opt for higher 'HiFi" quality output transformers, the sound quality should improve even more. No power increase over a cheaper transformer with the proper output impedance, just sound quality improvement.
The design of many of these console amps is sound. Where they cut corners was in places like the output transformers. In fact, many specifically chose transformers and coupling capacitors so as to limit the deep bass. This was to help eliminate feedback through the turntable when playing records. Normally, if you use the power amp as a stand alone unit, the power transformer is more then up to the task since it was chosen not only to power the amp but also the preamp and, if so equipped, tuner. So, the power supply is generally well up to the task of powering just the power amp chassis. Put in a nice set of Hammond hifi transformers and that thing should really sing. The great thing about the hifi transformers Hammond produces is that they have 4, 8, and 16 ohm taps on their secondary winding so you can use most any speaker . Make sure you research the proper primary impedance you will need for the type of output tubes you are using. 6V6 and EL84 types like 8000 - 10,000 ohm transformers while 6L6, EL34 and 6550's prefer 4300 - 6600ohm transformers. Make sure the transformer is rated at or above the power output of the amp. These transformers are a bit larger then the OEM ones that come in console amps. But most of these amps have enough extra space on the chassis to handle slightly larger output transformers. I have done the output transformer upgrade to a console amp for a guy and the sound was amazing. Like night and day in comparison to the sound with the original transformers.
The design of many of these console amps is sound. Where they cut corners was in places like the output transformers. In fact, many specifically chose transformers and coupling capacitors so as to limit the deep bass. This was to help eliminate feedback through the turntable when playing records. Normally, if you use the power amp as a stand alone unit, the power transformer is more then up to the task since it was chosen not only to power the amp but also the preamp and, if so equipped, tuner. So, the power supply is generally well up to the task of powering just the power amp chassis. Put in a nice set of Hammond hifi transformers and that thing should really sing. The great thing about the hifi transformers Hammond produces is that they have 4, 8, and 16 ohm taps on their secondary winding so you can use most any speaker . Make sure you research the proper primary impedance you will need for the type of output tubes you are using. 6V6 and EL84 types like 8000 - 10,000 ohm transformers while 6L6, EL34 and 6550's prefer 4300 - 6600ohm transformers. Make sure the transformer is rated at or above the power output of the amp. These transformers are a bit larger then the OEM ones that come in console amps. But most of these amps have enough extra space on the chassis to handle slightly larger output transformers. I have done the output transformer upgrade to a console amp for a guy and the sound was amazing. Like night and day in comparison to the sound with the original transformers.
