Response Audio started the Jolida upgrade over 20 years ago. We have since The Jolida 3205 modification is more than just a parts replacing upgrade. Anybody can swap out parts. What you get with the 3205 modification is a complete strip-down of the amplifier and redesigned input stage. 


When your unit arrives, it is first tested to make sure everything is in proper working order BEFORE tear down and rebuild. If you are having problems with your unit, please mention this to us prior to sending it in for the modification.

When we are finished upgrading your unit, the only original parts remaining are the transformers. 


You can expect your "new" Jolida amplifier to be more focused throughout the frequency ranges, a more focused soundstage and have better dynamics control.


For the audiophile on a budget, why spend your hard earned money on a new amplifier when you can save thousands of $$$$ and transform your older Jolida into a contender with $3K units. Transform your older Jolida amplifier into something that will compete with much more expensive units on the market and still maintain that classic nostalgic tube amp look.


The 3205 modification allows you to use EL34, KT77, 6550 or KT88 tubes in any of the amplifiers mentioned. All that is needed to do is install tubes of your choice and bias accordingly. Bias instruction sheet included.

Jolida 3205 Modification

​Includes all JD302A/B and JD502A/B

Modification Details

  • * The 12AX7 input stage is removed and redesigned/replaced with a Class A input stage built around the 12AU7 dual triode. The B+ power supply is redesigned to accommodate this new circuit and a new set of 12AU7 tubes are included.
  • * Dynamicap coupling capacitors are used in the coupling positions to maintain the smooth sound that made these amplifiers so popular.
  • ​*  ClarityCap capacitors are using in the signal ground locations
  • * Dale/Vishay 1% high wattage resistors used at power tube cathode grounds.
  • * A combination of Kiwame, Dale/Vishay and high quality Carbon Film resistors used throughout the signal path.
  • ​*  All power supply and bias supply capacitors replaced with higher capacitance, lower ESR pieces.
  • * Power supply filter capacitors bypassed with high voltage ClarityCap pieces.
  • * Power supply diodes upgraded to Fairchild "Ultra Fast - Soft Recovery" pieces.
  • * Volume control upgraded depending on model and current control used. You may choose have two mono volume controls used and eliminated the balance control. (price NOT INCLUDED in pricing below).
  • * Volume control can be removed and amplifier can be used as straight power amplifier.
  • ​* Internal signal wiring replaced with Cryogenically Treated, Silver Plated with Teflon Dialectric
  • * RCA input/output connectors replaced with higher quality pieces.
  • * Balance control bypassed or replaced with much higher quality Alps units. (optional)
  • * High quality Silver Solder used throughout.
  • * Biased and bench tested.
  • * System tested for minimum of 12 hours
  • * Labor 6-8 hours
  • ​* Limited 1 year parts and labor warranty


  • Pricing:
    ​$945 as stated above

  • ​Volume control upgrade - inquire
  • Dual mono carbon volume controls - $25