Hi peeps
I have a rotel RC960BX pre amp, I was just looking inside, more of a newby tinkerer than a full on DIY system maker But I was thinking maybe I could get a better performance if i upgraded the opamps?
Heres the list of current opamps..
on the left near the headphone inputs is a JRC 4556D
what seems off the tone controls is a Signetics NE5532AN
and then in the centre just off the volume switch is another one exactly the same (Signetics NE5532AN)
Now near what im sure is the phono preamplifier stage?? is 2 Signetic NE5534AN, and two TL071CP.
(could it be, that one set is for MM, and the others for MC?)
I have from trying different opamps in the Cd player, have these Opamps, spare
BB OPA604AP times 2
BB OPA2134PA " "
BB OPA2604AP " "
AD OP27EP IC " "
Would any of these be of good improvement over the stock ones?
A bit irritating but it wont let me upload the photo of the insides of the Amp , even though the file is 400KB?
thanks for any advice or help
I have a rotel RC960BX pre amp, I was just looking inside, more of a newby tinkerer than a full on DIY system maker But I was thinking maybe I could get a better performance if i upgraded the opamps?
Heres the list of current opamps..
on the left near the headphone inputs is a JRC 4556D
what seems off the tone controls is a Signetics NE5532AN
and then in the centre just off the volume switch is another one exactly the same (Signetics NE5532AN)
Now near what im sure is the phono preamplifier stage?? is 2 Signetic NE5534AN, and two TL071CP.
(could it be, that one set is for MM, and the others for MC?)
I have from trying different opamps in the Cd player, have these Opamps, spare
BB OPA604AP times 2
BB OPA2134PA " "
BB OPA2604AP " "
AD OP27EP IC " "
Would any of these be of good improvement over the stock ones?
A bit irritating but it wont let me upload the photo of the insides of the Amp , even though the file is 400KB?
thanks for any advice or help
There will be many opinions here I suspect, but I think the NE5532AN is a good choice and should be left in (at least until you've tryed the others). I would start with the 4556's. Then I would approach the TL071's (which are probably in a low noise application).
I think the OP27 will be better than the 4556, but not the 5532.
I think the OP27 will be better than the 4556, but not the 5532.
I know what your saying about them being dependant on other applications, point taken, i was just wodering with the experience of those that know of a like kind OPamp.
Thanks for the info Indm, and the advice Infinia. Cant find a Schematic for the Rotel anywhere.
Was kind of hoping for a simple drop in, here and there, but im srprised the NE5532AN, is one of the best, but, this preamp did however only retailing for £150/$300, did turn the heads of HIFI Choice, and they can be quite damming. Makes me wonder if im going to make any vast improvement. Still all info is welcome
Thanks for the info Indm, and the advice Infinia. Cant find a Schematic for the Rotel anywhere.
Was kind of hoping for a simple drop in, here and there, but im srprised the NE5532AN, is one of the best, but, this preamp did however only retailing for £150/$300, did turn the heads of HIFI Choice, and they can be quite damming. Makes me wonder if im going to make any vast improvement. Still all info is welcome
hi
Since you are looking at loads of choices for op-amps, you could obtain the data sheets for the pin for pin types and rank them in order of SR , (e)n, (i)n & GBW specs. Use the data in a chart format as a basis for your initial selections.
Finally conduct listening evaluations. Come back and publish a report.
Since you are looking at loads of choices for op-amps, you could obtain the data sheets for the pin for pin types and rank them in order of SR , (e)n, (i)n & GBW specs. Use the data in a chart format as a basis for your initial selections.
Finally conduct listening evaluations. Come back and publish a report.
I just remembered this.
It is IIRC seven pages and IMO very interesting considering your current needs.
http://www.zero-distortion.com/tests/opamps/opamps.htm
It is IIRC seven pages and IMO very interesting considering your current needs.
http://www.zero-distortion.com/tests/opamps/opamps.htm
Guess what ive just been doing?. I have taken out the stock amps, and replaced more expensive ones of the same ilk, checked all the polaritys, and for the same designs.I replaced the JRC 4556D with a BB OPA2134PA
the two Synetics? NE5532AN's I replaced with BB OPA2604AP
I havent as far replaced what i think is the phono stage TL071CP,
And the SYnetics? NE5534AN, i have some Analogue devices that match these..OP27EP they are quite expensive. to be honest i use the MM stage, if one set are for the MM, and the other for the MC, i would prefer to replace the MM. As i dont have a MC cartridge for now, but I dont really know if they work in series of two together, or seperate,
So far....
It all sounds marginally better, no real wow factor, the opamps were decent enough, but there is definitely an air of detail and richness in the sound, and a tad more weight. i had noticed, from CD to Amp, that the playback through headphones in the Amp, sounded ever so slightly shrouded, a bit cold sounding. Now its what i call richer and full. through speakers as well
Perhaps thats the Burr Brown touch.
Im pretty annoyed i cant upload a simple pic of 400Kb
Im really looking for a decent upgrade for the TL071CP now
I'll be totally honest infinia, you know those monkeys they trained to fit the square block into the square hole, and the ball into the round one. thats my understanding of electronics. i can make an amplifier if someone shows me, but on my own I dont have the nouse or the focus to understand schematics.
Ive fixed synths and quad amps, rehoused a T amp, and Im just really finding a project, thinking how can that work, or whats the simplest way to make it sound better, and just learning the bare basics.
heres my technical knowledge, if i see the PDF Opamp diagram matches up with one ive already got , it might not blow it up!!, lol
but im learning all the time, also not to get out of my depth, this preamp cost me £40, so if i screw it up, even though im On invalidity benefit, Its no great loss. And if i do get electrocuted, maybe, the Shock will cause my Arrythmia to leave
As always thanking you all for advice, but miffed i cant upload pics only 400KB's
In general it safe to exchange FET input opamps with FET input and BJT with BJT. I would replace the TL071 first, as they rather mediocre and bit noisy. As people previously said, I would agree to leave NE5532/4, as its rather good opamp, some people recall it a bit bright, but I like it as it is.
In phono stage you will prefer something lownoise but it depends on the system you are using as some opamps have low current noise and some have low voltage noise. I would try OPA604 in place of TL071.
You also can browse http://www.dself.dsl.pipex.com/ampins/webbop/opamp.htm for more info.
In phono stage you will prefer something lownoise but it depends on the system you are using as some opamps have low current noise and some have low voltage noise. I would try OPA604 in place of TL071.
You also can browse http://www.dself.dsl.pipex.com/ampins/webbop/opamp.htm for more info.
Your 400kB file, is it a JPEG? I use Paint shop pro and it allows me to set the compression level on a JPEG in steps, right down to utter blockiness. I imagine other programs would allow accessing this feature of JPEG's.
IIRC, and notwithstanding application dependent differences, the OP27 sounded to me a little more accurate than the NE5534AN but also flatter (in a clinical way), less life. At the end of the day, I preferred the 5534.
IIRC, and notwithstanding application dependent differences, the OP27 sounded to me a little more accurate than the NE5534AN but also flatter (in a clinical way), less life. At the end of the day, I preferred the 5534.
Hi
Maybe you can try this.
JRC 4556D = no change
NE5532AN's = no change
TL071CP = OPA2134PA
MM stage = OP27 or even something even better i.e. closer to the i current noise of a OP37.
Current noise usually dominates in MM high impedance circuits.
But depending on the powersupplies contribution may not hear that much improvement.
Connect the TT cartridge and without records, listen to the hiss levels at equal gain settings.
Maybe you can try this.
JRC 4556D = no change
NE5532AN's = no change
TL071CP = OPA2134PA
MM stage = OP27 or even something even better i.e. closer to the i
current noise of a OP37.Current noise usually dominates in MM high impedance circuits.
But depending on the powersupplies contribution may not hear that much improvement.
Connect the TT cartridge and without records, listen to the hiss levels at equal gain settings.
AndrewT said:
I agree wholeheartedly that using a discrete opamp will give a big improvement. The few times I compared an IC opamp with a discrete one (either as central part of a power amp or as a preamp) the discrete one came out on top, big time. Even when compared with opamps such as the OPA627. So I would say your suggestion holds for the other opamps as well.
But building a discrete opamp might be a bit difficult (even more so for a dual one such as a NE5532), since he is - in his own words - more of a newby tinkerer than a full on DIY system maker...
Remco
thanks for your input guys!!
Well, as i was limited to money, and also the OPamps, i gave in my list. I did this, and to be honest, It hasnt blown up, and sounds pretty dam good.
Ive replaced the JRC 4556D with a Burr Brown OPA2134PA, Sounds better to my ears
replaced the two NE5532AN with two OPA2604AP, definitely more authority in the bass, and a slightly richer sound. I think these rotels are great value for money. I was litening wuite happily to a Bill Frisell CD, and it sounded very musical in my HD580's.
Before i remember it being slightly colder, i think its all *luckily balanced well with the Tubed CD player, and maybe, It could be a bit too clinical and bright on a normal CD player, but im really happy with the little improvements.
I have not attempted the Phono stage yet.
with regards to the Jpegs, My pictures were originally 800KB JPegs, then i chaged them into 400KB GIFS, so Im not too sure why they wont upload, perhaps this might work, im using a freinds site to upload picccys
This is an overhead showing the Headphone OPAMp on the left (JRC 4556D), and the next two to the right NE5532aN, and up on the far right is what i assume to be the phono stage
http://groups.msn.com/Spiritsoffreedomandfun/virus.msnw?action=ShowPhoto&PhotoID=59
http://groups.msn.com/Spiritsoffreedomandfun/virus.msnw?action=ShowPhoto&PhotoID=58
and heres a closeup, (with my bad camera) of the 4 opamps, TL071CP, and NE5534AN
http://groups.msn.com/Spiritsoffreedomandfun/virus.msnw?action=ShowPhoto&PhotoID=57
I have 2 OPa604AP spare and a pair of analogue devices OP27EP IC,s. ( these sounded good in place of the OPamps i had in my AH Njoe TJoeb CD player(OPA604AP, but essentialy Im going to put the OP627,s BB in that, so these are spares)
Well, as i was limited to money, and also the OPamps, i gave in my list. I did this, and to be honest, It hasnt blown up, and sounds pretty dam good.
Ive replaced the JRC 4556D with a Burr Brown OPA2134PA, Sounds better to my ears
replaced the two NE5532AN with two OPA2604AP, definitely more authority in the bass, and a slightly richer sound. I think these rotels are great value for money. I was litening wuite happily to a Bill Frisell CD, and it sounded very musical in my HD580's.
Before i remember it being slightly colder, i think its all *luckily balanced well with the Tubed CD player, and maybe, It could be a bit too clinical and bright on a normal CD player, but im really happy with the little improvements.
I have not attempted the Phono stage yet.
with regards to the Jpegs, My pictures were originally 800KB JPegs, then i chaged them into 400KB GIFS, so Im not too sure why they wont upload, perhaps this might work, im using a freinds site to upload picccys
This is an overhead showing the Headphone OPAMp on the left (JRC 4556D), and the next two to the right NE5532aN, and up on the far right is what i assume to be the phono stage
http://groups.msn.com/Spiritsoffreedomandfun/virus.msnw?action=ShowPhoto&PhotoID=59
http://groups.msn.com/Spiritsoffreedomandfun/virus.msnw?action=ShowPhoto&PhotoID=58
and heres a closeup, (with my bad camera) of the 4 opamps, TL071CP, and NE5534AN
http://groups.msn.com/Spiritsoffreedomandfun/virus.msnw?action=ShowPhoto&PhotoID=57
I have 2 OPa604AP spare and a pair of analogue devices OP27EP IC,s. ( these sounded good in place of the OPamps i had in my AH Njoe TJoeb CD player(OPA604AP, but essentialy Im going to put the OP627,s BB in that, so these are spares)
Hi,
as someone stated before, without knowing the schematic, you stay on the safe side replacing jfets by jfets, bjts by bjts.
Eg. NE5532 by OPA2227.
NE5534 by OPA227 (or OPA27) then.
OR well, if it's the phono stage (gain of 40dB or so) better use an OPA228 or OP37
And TL071 by OPA134, OPA604 or OPA627 (but you didn't want to spend THAT much money...)
Not by OPA2134 as suggested before, because that's a dual chip and the TL071 is a single chip!
If the NJM4556 is the headphone driver, you could try a high current chip in a SO-8 case soldered on a SO to DIP adapter.
I looked for a nice headphone op-amp in a DIP package and I really couldn't find any!
Those chips which are able to drive low impedance headphones with low distortion are all in SOIC...
But that solution is probably not fine for all of those nice SOIC chips, because many of them are high speed and could give stability problems in an adapter. I didn't try it yet, but the AD8397 could possibly work and many recommend that chip lately.
Cheers,
Dominique
as someone stated before, without knowing the schematic, you stay on the safe side replacing jfets by jfets, bjts by bjts.
Eg. NE5532 by OPA2227.
NE5534 by OPA227 (or OPA27) then.
OR well, if it's the phono stage (gain of 40dB or so) better use an OPA228 or OP37
And TL071 by OPA134, OPA604 or OPA627 (but you didn't want to spend THAT much money...)
Not by OPA2134 as suggested before, because that's a dual chip and the TL071 is a single chip!
If the NJM4556 is the headphone driver, you could try a high current chip in a SO-8 case soldered on a SO to DIP adapter.
I looked for a nice headphone op-amp in a DIP package and I really couldn't find any!
Those chips which are able to drive low impedance headphones with low distortion are all in SOIC...
But that solution is probably not fine for all of those nice SOIC chips, because many of them are high speed and could give stability problems in an adapter. I didn't try it yet, but the AD8397 could possibly work and many recommend that chip lately.
Cheers,
Dominique
I have a RC-960BX somewhere...
- and traced the circuit to paper...
The gaincircuit would be like fig 10 here: http://hjem.get2net.dk/bencar/opamp/opamp1.htm
I changed op-amp to AD825x2, and gain-resistors from 10k-1k to 8,2k-1,6k, and replaced DC-blocking caps with good 10uF bi-polars. (A lot of polarized BlackGates are used in the signal-path, they are better used elswere...)
Also added a blue motorized Alps pot and remote-kit from a diy-member from Denmark...
No way near a X-BoSoZ & attenuator, but ok...
Arne K
- and traced the circuit to paper...
The gaincircuit would be like fig 10 here: http://hjem.get2net.dk/bencar/opamp/opamp1.htm
I changed op-amp to AD825x2, and gain-resistors from 10k-1k to 8,2k-1,6k, and replaced DC-blocking caps with good 10uF bi-polars. (A lot of polarized BlackGates are used in the signal-path, they are better used elswere...)
Also added a blue motorized Alps pot and remote-kit from a diy-member from Denmark...
No way near a X-BoSoZ & attenuator, but ok...
Arne K
Will changing the Pot make a difference to the sound?, its one of those dual Rotel balance types, a small disc overlyed on an inner thicker disc, that works left and right channels. In the end I dont need the balance feature, and have never used it on any amplifier before. ok perhaps to test speakers
And yes dominique your right
**Not by OPA2134 as suggested before, because that's a dual chip and the TL071 is a single chip!**
Luckily i have checked , duals and singles
***And TL071 by OPA134, OPA604 or OPA627 (but you didn't want to spend THAT much money...)**
I might just
And yes dominique your right
**Not by OPA2134 as suggested before, because that's a dual chip and the TL071 is a single chip!**
Luckily i have checked , duals and singles
***And TL071 by OPA134, OPA604 or OPA627 (but you didn't want to spend THAT much money...)**
I might just
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