Eros v1: Bass is low after capacitor upgrade. [resolved]

[ideal.hat]

Hello there.

I finished my Eros version 1 few weeks ago and everything went as planned.

I have now replaced the 1.50uf 630v Solen caps with Mundorf MCap EVO Silver Gold 0,47uf 450v caps.

I feel like I have lost power in the low end lets say from 35 - 90Hz. Its there but low.

I know I am going pretty far away in specs from stock, but I do that after reading alot of threats about the subject in here.
I hope I am not misunderstanding something..

Either I am doing something wrong, or the new caps need burn-in.

In case I just need to burn them in, what would be the most cost efficient way to do that?
I dont want to use my Nagaoka MP200 for then job and I would not like to spend a lot of money on a inverse RIAA  filter.

Thanks in advance.

[Deke609]

For cap break-in method, see here: https://bottlehead.com/smf/index.php?topic=11316.0

As for loss of bass, it could be either the cap value, the newness of the cap, or both.

Cap value: others with more knowledge and experience will hopefully chime in on this issue. My understanding is that depending on their value, caps can filter out or reduce the frequencies at either the high end (using a large value cap) or the low end (using a low value cap). I believe that Bottlehead picks values for caps in the signal path with the aim of balancing desired high and low frequency response. But I've read Paul Joppa suggest in many threads that as a rule of thumb one can go as much as twice or half as big as the stock value.  In your case, you have gone 1/3 as big -- that could conceivably be limiting your bass.  But I wouldn't draw any conclusions until you've given the new caps time to break-in.

Break-in: In my limited experience, film caps in the signal path do all kinds of crazy things as they break-in. Typically, I find they sound ok when first installed, but then worsen after 5+ hours. I am at day 4 of breaking in some new Claritycaps right now (in the amp using dummy load resistors on the speaker outs, not using Grainger's method): after 24 hrs, the bass was muted and muffled, and the treble screechy with unlistenable sibilance. Yesterday, with 70 hrs or so, the amp started to sound pretty good, but not there yet.

My suggestion would be to give the caps at least 100 hrs of use before deciding on whether you need more bass. If bass is lacking after the cap is mostly burned in, you can test whether adding a larger cap value in parallel with the Mundorf will fix the issue by putting back the 1.5 uF Solen in parallel with the 0.47 uF, for a total 2 uF (assuming you kept the Solen). Or get three cheap film caps (say, 0.33uF, 0.47uf and 1.0 uF) and add them in parallel to see what suits your taste. And once you have a value that works for you, you could decide on whether you want to invest in a more pricey boutique version.

cheers,

Derek

[Paul Birkeland]

What's in the chain after your Eros?

[ideal.hat]

Thank you Derek: I will look more into the filter, I might experiment a bit with the capacitors once I receive feedback on my current configuration.

PB: Its a bit complicated, so I need to give you few examples. I am experiencing this with all chain configuration.
Rega P3 > Eros > Mainline > HD800S/HD820/HD650/DT1770Pro
Rega P3 > Eros > Crack+Speedball > HD800S/HD820/HD650/DT1770Pro
Rega P3 > Eros > Sennheiser HDVA600 > HD800S/HD820/HD650/DT1770Pro
Rega P3 > Eros > MF M5si > B&W CM1S2 + 2x Dali E-9F subwoofers (pre out from M5si to M1Hpap to control Sub volume.

Its a bit interesting with the speaker setups, where I can control the bass volume, I can turn it up too much and it gets boomy, but even then, I feel like I am missing bass that used to be there.

I did not have this issue with the stock Solen 1,5uf 630v.

[Paul Birkeland]

For the Mainline, HDVA600, and probably even the M5, 0.47uF is probably on the low side.  For the HDVA in particular, going up to 2-3uF would be a good idea.

[ideal.hat]

Its is valuable information, thank you.

Should I then perhaps to connect the Mundfort 0,47uf to the Solen 1,5uf and see how I like it?
and in case the outcome is good, then I can go for a Mundorf MCap EVO Silver Gold 2uf 450v?

[ideal.hat]

Hello again.

I have put the stock Solen 1,5uf back in and ordered Mundorf MCap EVO Silver Gold 2.2uf 450v.

Thanks for the help, I hope this will sound fantastic

[ideal.hat]

Hello Paul and those might be interested.

I just wanted to check in and inform about my process.

I have now installed the Mundorf MCap EVO Silver Gold 2,2uf 450v caps
I believe the sub frequencies are back and it sounds good to my ears right out of the box.
Hopefully it will sound even better after 100+ hour.

Now I have 3 remaining questions, keep in mind that I am learning so this is a bit basic

1. If I would like to add the 0,47uf to the 2.2uf to get a total of 2,67uf capacity. Would I then connect them in parallel to combine the capacity (= 2,67uf) ?

2. I have attached a picture on how I think the parallel connection should be, it would be great if someone could verify it or correct me.

3. What would be the easiest way for a beginner like me to burn in the new capacitors without using my cartridge?
Would it be possible to play  a special audio file that is made for the job just from a normal source (phone or computer),
or would I need to buy or build a inverse RIAA filter?

I have attached some pictures of my Eros. I still have the task waiting for me to treat the base of my Mainline and Eros.

[Paul Birkeland]

Yes, that is how you connect capacitors in parallel, though you may not prefer the extra caps in parallel with what you have now.

To burn the Eros in, you can use your phone on its lowest volume setting plugged into the Eros and playing a music file on repeat.

[ideal.hat]

Thank you for the clarification.

I might test the parallel connection later to see if I like it.

I am putting a burn-in load now from a tablet at a lowest volume as we speak.

Do I need to have an amplifier connected and even eventually headphones/speakers connected to it in order to draw load through those capacitors or is it fine just like you said with only source at low volume going in and nothing else connected?

[Paul Birkeland]

Nothing needs to be connected at the output.

[Doc B.]

The resistor across the output in the Eros is adequate to drain the charge developed by the AC music signal off the output side of the cap. It doesn't need to be connected to anything else. For sake of clarity, you don't "draw load".  A load on a component will cause current to be drawn through the component. The lower the impedance of the load, the more current that will be drawn.

[ideal.hat]

Thank you all for answering all my questions.

I do not have anything more in this regards.

Excellent support like always..

[ideal.hat]

I have now been running a burn-in track for 30 hours and I am liking the results with my gear (Mainly with Mainline and M5si)

The bass feels a bit boosted (compared to stock) and I think that is a good thing in my case since I want my vinyl playback to be warm and tube-y.
If I want more neutrality, I go for my digital setup M6DAC or my Primera R32 SS phono stage.

There is definitely more bass with the Mundorf MCap EVO Silver Gold 2,2uf then with the 1,5uf stock Solen.
Its maybe not for everyone but I dig it so far.

I am looking forwards how it will sound after 100+ hours.