SX-838 modifications?

[sstern1966]

I have recently acquired an SX-838 in splendid physical condition. I love the looks (not that important), but the sound has less bottom than I would hope for. Hence a bit less of a soundstage and sonic headroom than I would like. Otherwise, excellent sound reproduction.

Does anyone know of any modifications that have proven successful on this line?

 

[rcs16]

I'd suggest to re-cap it first.

 

[sstern1966]

I'd suggest to re-cap it first.

Before doing that, I wish I knew if it had the sound I am looking for when it came out of the box....It's a handsome receiver, but doesn't seem to garner rave reviews. My comparison piece is a Realistic STA-240---nothing to brag about, but has much deeper sound.

 

[gbroot]

I've not owned all of the x3x series but have had the 737 and the 939. Both had more than enough bass. Don't be afraid to use tone controls if you haven't. Also does it have a tone control switch? If so, then toggle it so that tone controls are active. Otherwise, most likely tired caps and a number of other issues. Most 40+ year old receivers are going to have issues. Good luck.

 

[loweran]

All the X3X I have redone seemed to be that way. They don’t really wake up till you get the power, amps and control board recapped. My experience anyway.

My daughter runs an 838 and trust me there is plenty of low freq to shake the house.

 

[ranch 22b]

Have you tried using the Loudness switch? I think Pioneer did a good job with their Loudness contour on their vintage receivers.

I know it's not "pure" but I use my SX-636 with the Loudness switch on and the Bass and Treble controls turned down a couple of clicks (at low to medium volume).

 

[sstern1966]

Have you tried using the Loudness switch? I think Pioneer did a good job with their Loudness contour on their vintage receivers.

I know it's not "pure" but I use my SX-636 with the Loudness switch on and the Bass and Treble controls turned down a couple of clicks (at low to medium volume).

I gave it two weeks of consistent listening. You are right in that the loudness is decent. Still, compared to other "lesser" receivers, less of the three dimensionality that I was hoping for from this receiver (it was given to me by its only owner....it sat in a tool shed for 20 years or so). Your response is helpful....it is hard to know if a receiver sounds like it is supposed to. I certainly don't want to buy another one to compare sided by side ;-)

 

[sstern1966]

All the X3X I have redone seemed to be that way. They don’t really wake up till you get the power, amps and control board recapped. My experience anyway.

My daughter runs an 838 and trust me there is plenty of low freq to shake the house.

How does it compare to other decent receivers that you have? I'm using a 65 wpc Realistic as a comparison. With 50wpc, the Pioneer should be perfectly fine in comparison, although it is 5 years older. I don't want to recap only to find that I'm being too demanding in my taste.

 

[loweran]

It sounds warm and full to me. Speaker selection will also make a difference. I have the 737, 838 and 1010. Also have a sx-1000td, and newer stuff. I really like them all to be quite honest. The 737 is probably the sweet spot in terms of overall tone. The 1010 sounds great too and has plenty of power.

Problem is, you will never know unless you can find one that has been redone. Would you be doing the work yourself?

 

[sstern1966]

It sounds warm and full to me. Speaker selection will also make a difference. I have the 737, 838 and 1010. Also have a sx-1000td, and newer stuff. I really like them all to be quite honest. The 737 is probably the sweet spot in terms of overall tone. The 1010 sounds great too and has plenty of power.

Problem is, you will never know unless you can find one that has been redone. Would you be doing the work yourself?

I'd be having it done by someone who knows better. I've never done it before, and although I'm tempted, I'd rather play on a lesser piece of equipment.

 

[loweran]

Well, that may present a barrier. Sending it off will cost hundreds more than if you did it yourself. You have caps that are over 40 years old in it. It's not going to sound like it once did until you address that.

 

[ranch 22b]

Something that helped my SX-636 sound better was simply cleaning the fuse holders on the rear of the receiver.

 

[sstern1966]

Well, that may present a barrier. Sending it off will cost hundreds more than if you did it yourself. You have caps that are over 40 years old in it. It's not going to sound like it once did until you address that.

I plan to price it next time I head into the "big city" (I live outside of Pittsburgh). I could see DIYing if the price is too steep.

 

[sstern1966]

Something that helped my SX-636 sound better was simply cleaning the fuse holders on the rear of the receiver.

Hmmm. I cleaned just about every other part!!!! I might just as well give that a try! And those are really easy to access!

 

[gbroot]

I'd say if it was sitting in a storage shed for 20 years a good number of the caps dried out. Contrary to the way it would seem, no use for a long period of time can be way worse than regular use.

 

[rkgren1]

My sx-636 (no work done to it), but which by all appearances has lived a charmed, air conditioned life, is really strong in the low frequencies.
My sx-950 was rather thin and reedy until a refurbishing. Now it's quite strong on the low end, and it sounds powerful across the whole spectrum.

I agree with most of the other posts. You likely have aging parts inside your 838.
I bet it will change greatly for the better with fresh capacitors and transistors.

 

[larryderouin]

The one thing that hasn't been addressed is your speaker selection. Some speakers don't have synergy with some receivers/amps while with others it makes them sound like $1,000,000,000,000. Make sure the speakers have been recapped 1st.

The x3x series do have a tendency to be a bit thin with speakers that are a poor match. I've found that most speaker with a sensitivity of 91db/1m/1w or higher will match quite well with any of the x3x series. However with lower sensitivity speakers, use of the tone controls, and the loudness control are needed in most cases. Having said that, all of the x3x are direct coupled to the speakers (no output caps). Cap coupled amps/receivers tend to have more bass at lower levels with the bass turned down and the loudness off than direct coupled units with the controls centered. PIONEER tried to make the x3x series somewhat neutral sounding and with some speakers they succeeded. Once you have speakers for one unit in the series, I've found they can be used all across the board for the x3x's. (I have the 434, 737, 939, and sold my 1010).

 

[sstern1966]

The one thing that hasn't been addressed is your speaker selection. Some speakers don't have synergy with some receivers/amps while with others it makes them sound like $1,000,000,000,000. Make sure the speakers have been recapped 1st.

The x3x series do have a tendency to be a bit thin with speakers that are a poor match. I've found that most speaker with a sensitivity of 91db/1m/1w or higher will match quite well with any of the x3x series. However with lower sensitivity speakers, use of the tone controls, and the loudness control are needed in most cases. Having said that, all of the x3x are direct coupled to the speakers (no output caps). Cap coupled amps/receivers tend to have more bass at lower levels with the bass turned down and the loudness off than direct coupled units with the controls centered. PIONEER tried to make the x3x series somewhat neutral sounding and with some speakers they succeeded. Once you have speakers for one unit in the series, I've found they can be used all across the board for the x3x's. (I have the 434, 737, 939, and sold my 1010).

I use a set of Klipsch SF-2 towers with a Velodyne subwoofer. When my friend gave me the receiver, he included a pair of JBL Decade 36s that still sound ok, but have fairly rotted foam. I have oddly enough not swapped them in since they are a bit heavy and I don't want to drag them around. Either way, the Klipsch sound nice in most situations. According to specs I found online, they are rated as 96db.

 

[loweran]

Bottom line is, it's not going to sound the way it should until you recap it, and replace key components to ensure it is in good working order. That will apply to any 40 year old audio equipment, including speakers, assuming they have the original parts installed.

If you don't want to take the chance, join the forum and put it up on Barter Town. It should move pretty quickly. Better yet, join the forum, get a good iron and dig in. You will get all the support you need to do the work, and it's a fairly easy receiver to work on. I did mine in about a day, granted it was my 3rd receiver to restore.