Thursday, January 28, 2021

"fiih-300" - Holton based 300W power amp


Once again a powerful 300W Holton based power amp using the upgraded 200W modules. These have the more powerful dual die power FETs installed to allow the modules to produce 300W into 8 ohms and 500 into 4. 80,000uf of 100V filter caps all snubbed and an RFI/EMI power filter.

An over size heatsink is used but still runs up to over 50C. Tranni is 500VAC but will be more than enough to drive the hardest loads to high volume. Once more excellent Holton bass depth and control. Clear, transparent mids. Allover an excellent sounding amp. 

Friday, January 15, 2021

“Sortilege” - enhanced Class D power amp


Another 180W Class D amp based on the hifimediy T4 module. This time the input caps have been upgraded to Mundorf EVO oils and an additional 22,000uf of Mundorf MLytic audio grade capacitance has been added to the PS. Total caps with onboard Nichicon is 32,000uf. The filter caps are snubbed. Enclosure is attractive two tone, earthed and fused. A RFI/EMI power filter has been added and a ferrite choke on the power cord to block RFI. A 500VA tranni does the grunt work and the onboard Motorola ultrafast/soft recovery diodes for the rectifying. 

The amp sounds excellent, clean, clear and fast with optimum bass control. For the extra work replacing the input caps and adding the better filter cap the sound quality has improved. Other amp builders who have heard it agreed and its new own is very pleased. So am I.