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Re: Gain Controls Vs Volume Controls

May 13th, 2024, 2:13 pm

SoundMods wrote:Finally -- someone in this group gets it. Yes they're expensive -- but it is a one-time purchase. :thumbup: :obscene-drinkingcheers:


Yup, that's what I figure.
In the worst case, I will move them into the next preamp.

Need to get bypass caps to go along with these.

Re: Gain Controls Vs Volume Controls

May 14th, 2024, 12:49 am

Cogito wrote:
SoundMods wrote:Finally -- someone in this group gets it. Yes they're expensive -- but it is a one-time purchase. :thumbup: :obscene-drinkingcheers:


Yup, that's what I figure.
In the worst case, I will move them into the next preamp.

Need to get bypass caps to go along with these.

Teflon caps are the perfect bypass caps for your selection. The combination forms a transparent and musical pass-through.

Re: Gain Controls Vs Volume Controls

May 14th, 2024, 6:12 am

An alternative (but more expensive) suggestion is to use Duelund Silver Foil wax paper and oil bypass caps. These, in combination with larger value Miflex, are a great combination that bring in the detail while maintaining the naturalness one gets from the Myflex, and, I presume, the similar sounding Jupiter caps (I have only have direct experience with using them with Miflex). Charlie Phelps thinks these are about 99% of the sound of the topline and hidiously expensive Duelund Cast Cu-Ag PIO caps, though I admit that the cost of the bypass caps probably exceeds the cost of the main capacitor in this configuration.

https://partsconnexion.com/collections/ ... -capacitor

Personally, I would try it initially without the bypass caps, the Miflex and Jupiter caps are excellent by themselves, and then add the bypass in each position.

Re: Gain Controls Vs Volume Controls

May 14th, 2024, 1:39 pm

David McGown wrote:An alternative (but more expensive) suggestion is to use Duelund Silver Foil wax paper and oil bypass caps. These, in combination with larger value Miflex, are a great combination that bring in the detail while maintaining the naturalness one gets from the Myflex, and, I presume, the similar sounding Jupiter caps (I have only have direct experience with using them with Miflex). Charlie Phelps thinks these are about 99% of the sound of the topline and hidiously expensive Duelund Cast Cu-Ag PIO caps, though I admit that the cost of the bypass caps probably exceeds the cost of the main capacitor in this configuration.

https://partsconnexion.com/collections/ ... -capacitor

Personally, I would try it initially without the bypass caps, the Miflex and Jupiter caps are excellent by themselves, and then add the bypass in each position.


Installed the 1mf Jupiter output caps yesterday. The effect is immediately audible. They added sweetness to the treble.

In my preamp, there are three coupling caps. 0.1mf caps for input and interstage coupling and 1mf for output coupling. For the output coupling, do I use one 0.01mf cap or a combo of 0.1mf and 0.01mf coupling caps?

Re: Gain Controls Vs Volume Controls

May 14th, 2024, 1:49 pm

Use the 0.01 uF cap. I would suggest just bypassing the output coupling cap first, you might find the 0.1uF caps do not need bypassing.

Re: Gain Controls Vs Volume Controls

May 15th, 2024, 10:49 am

Cogito wrote:
David McGown wrote:An alternative (but more expensive) suggestion is to use Duelund Silver Foil wax paper and oil bypass caps. These, in combination with larger value Miflex, are a great combination that bring in the detail while maintaining the naturalness one gets from the Myflex, and, I presume, the similar sounding Jupiter caps (I have only have direct experience with using them with Miflex). Charlie Phelps thinks these are about 99% of the sound of the topline and hidiously expensive Duelund Cast Cu-Ag PIO caps, though I admit that the cost of the bypass caps probably exceeds the cost of the main capacitor in this configuration.

https://partsconnexion.com/collections/ ... -capacitor

Personally, I would try it initially without the bypass caps, the Miflex and Jupiter caps are excellent by themselves, and then add the bypass in each position.


Installed the 1mf Jupiter output caps yesterday. The effect is immediately audible. They added sweetness to the treble.

In my preamp, there are three coupling caps. 0.1mf caps for input and interstage coupling and 1mf for output coupling. For the output coupling, do I use one 0.01mf cap or a combo of 0.1mf and 0.01mf coupling caps?


Question Sashi: what is the input impedance of the load? Are you sure that the 1uF caps are sufficient to give you full bass response?

In any event, the Miflex caps by themselves are, as David described, excellent.

Don't forget the power supply caps. They are a part of the circuit and need to be bypassed. I don't know what your circuit is, but if you can replace the B+ caps (assuming they are electrolytic) with DC Link caps, you'll be pleasantly surprised at the improvement. Again, bypass the final stage of the filter with a small value (say, 0.1uF) Miflex or better.

Stuart

Re: Gain Controls Vs Volume Controls

May 15th, 2024, 10:56 am

I like using the CDE 942C series caps for power supply bypass, very good caps by themselves in signal path applications and alot cheaper than the Miflex. Keep the Miflex in the signal path. (Yes, I know that the power supply IS in the signal path for single ended circuits).

Re: Gain Controls Vs Volume Controls

May 15th, 2024, 11:07 am

Interesting, I've not seen a 'Hybrid' film cap before.
"....hybrid section design of polypropylene film, metal foils and metallized polypropylene dielectric..."

David McGown wrote:I like using the CDE 942C series caps for power supply bypass, very good caps by themselves in signal path applications and alot cheaper than the Miflex. Keep the Miflex in the signal path. (Yes, I know that the power supply IS in the signal path for single ended circuits).

Re: Gain Controls Vs Volume Controls

May 15th, 2024, 12:16 pm

I really like the CDE caps, best is use the versions with voltage ratings 1000V and above. Use these first, then consider upgrading in your DIY builds. You may not need to.

Shashi, I am a little concerned about the version of the Miflex caps you are using, I believe these are for speaker crossover application. For tube applications I would use the 600V version. The thicker and higher voltage films generally are better for tube circuits. There is a big size difference.

David


FerdinandII wrote:Interesting, I've not seen a 'Hybrid' film cap before.
"....hybrid section design of polypropylene film, metal foils and metallized polypropylene dielectric..."

David McGown wrote:I like using the CDE 942C series caps for power supply bypass, very good caps by themselves in signal path applications and alot cheaper than the Miflex. Keep the Miflex in the signal path. (Yes, I know that the power supply IS in the signal path for single ended circuits).

Re: Gain Controls Vs Volume Controls

May 15th, 2024, 12:43 pm

Question Sashi: what is the input impedance of the load? Are you sure that the 1uF caps are sufficient to give you full bass response?
FYI -- If the 1-ufd output couplers are looking into a 100K-ohm load they're good down to 1.7-Hz. Any issues a decade higher will still be below 17-Hz. :character-oldtimer:
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